bazel: Qualify build_file attributes with @zephyr in MODULE.bazel

When Zephyr is consumed as an external dependency via Bzlmod, repository
rules defined in Zephyr's MODULE.bazel (such as new_git_repository for
cmsis and cmsis_6, and http_archive for toolchain SDKs) resolve bare
//... labels against the root repository rather than @zephyr.

Qualify these build_file paths with @zephyr// so that downstream
projects can consume them without repository resolution errors.

Change-Id: Ie1c3b92148336cbffbea7e677406a78a2bd7a84a
Reviewed-on: https://pigweed-review.googlesource.com/c/third_party/github/zephyrproject-rtos/zephyr/+/462405

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index 81964e6..b552f92 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -30,7 +30,7 @@
 
 http_archive(
     name = "zephyr_sdk_xtensa_dc233c",
-    build_file = "//toolchain/xtensa:zephyr_sdk_xtensa_dc233c.BUILD",
+    build_file = "@zephyr//toolchain/xtensa:zephyr_sdk_xtensa_dc233c.BUILD",
     sha256 = "d5dcce629d7cc24b1d0a367447340c1d9fbcedc0a6ed99ee105c8f1fe87060b2",
     strip_prefix = "xtensa-dc233c_zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_xtensa-dc233c_zephyr-elf.tar.xz"],
@@ -38,7 +38,7 @@
 
 http_archive(
     name = "zephyr_sdk_arm",
-    build_file = "//toolchain/arm:zephyr_sdk_arm.BUILD",
+    build_file = "@zephyr//toolchain/arm:zephyr_sdk_arm.BUILD",
     sha256 = "21b85981cb5a1818d9bc53d82af80f208946ec038b982ff1907287572ed3a634",
     strip_prefix = "arm-zephyr-eabi",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_arm-zephyr-eabi.tar.xz"],
@@ -46,7 +46,7 @@
 
 http_archive(
     name = "zephyr_sdk_arc",
-    build_file = "//toolchain/arc:zephyr_sdk_arc.BUILD",
+    build_file = "@zephyr//toolchain/arc:zephyr_sdk_arc.BUILD",
     sha256 = "3b2c499772a6a56d8e72fda4db35d3f3443a75f287968fcf6e80657f3b4f48ca",
     strip_prefix = "arc-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_arc-zephyr-elf.tar.xz"],
@@ -54,7 +54,7 @@
 
 http_archive(
     name = "zephyr_sdk_arm64",
-    build_file = "//toolchain/arm64:zephyr_sdk_arm64.BUILD",
+    build_file = "@zephyr//toolchain/arm64:zephyr_sdk_arm64.BUILD",
     sha256 = "01c0cfe1daaab2d2a0f71165f11a066d983ef97e51c4a3753186afa6ae55c24b",
     strip_prefix = "aarch64-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_aarch64-zephyr-elf.tar.xz"],
@@ -62,7 +62,7 @@
 
 http_archive(
     name = "zephyr_sdk_mips",
-    build_file = "//toolchain/mips:zephyr_sdk_mips.BUILD",
+    build_file = "@zephyr//toolchain/mips:zephyr_sdk_mips.BUILD",
     sha256 = "6b0ee0f71bd1f2fd15d91950fced546b9542ba81dbcceff1456530ab95dac0bc",
     strip_prefix = "mips-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_mips-zephyr-elf.tar.xz"],
@@ -70,7 +70,7 @@
 
 http_archive(
     name = "zephyr_sdk_riscv",
-    build_file = "//toolchain/riscv:zephyr_sdk_riscv.BUILD",
+    build_file = "@zephyr//toolchain/riscv:zephyr_sdk_riscv.BUILD",
     sha256 = "01750834c471fbdb335c1b8b8aee17010a1968938957db85640c366235771a38",
     strip_prefix = "riscv64-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_riscv64-zephyr-elf.tar.xz"],
@@ -78,7 +78,7 @@
 
 http_archive(
     name = "zephyr_sdk_rx",
-    build_file = "//toolchain/rx:zephyr_sdk_rx.BUILD",
+    build_file = "@zephyr//toolchain/rx:zephyr_sdk_rx.BUILD",
     sha256 = "d3200cde7ab547094024900a6d289a62f0be05958d89131704d03e3e9499112d",
     strip_prefix = "rx-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_rx-zephyr-elf.tar.xz"],
@@ -86,7 +86,7 @@
 
 http_archive(
     name = "zephyr_sdk_sparc",
-    build_file = "//toolchain/sparc:zephyr_sdk_sparc.BUILD",
+    build_file = "@zephyr//toolchain/sparc:zephyr_sdk_sparc.BUILD",
     sha256 = "d11759fbe6accf4106601c79864270494ab6b1e6539fd29e8223e8e124fa609e",
     strip_prefix = "sparc-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_sparc-zephyr-elf.tar.xz"],
@@ -94,7 +94,7 @@
 
 http_archive(
     name = "zephyr_sdk_x86",
-    build_file = "//toolchain/x86:zephyr_sdk_x86.BUILD",
+    build_file = "@zephyr//toolchain/x86:zephyr_sdk_x86.BUILD",
     sha256 = "960fd8d8690ce130b141736e494a7bae7da1f96956f8da405de66429670b62e9",
     strip_prefix = "x86_64-zephyr-elf",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/toolchain_gnu_linux-x86_64_x86_64-zephyr-elf.tar.xz"],
@@ -102,7 +102,7 @@
 
 http_archive(
     name = "zephyr_sdk_llvm",
-    build_file = "//toolchain/llvm:zephyr_sdk_llvm.BUILD",
+    build_file = "@zephyr//toolchain/llvm:zephyr_sdk_llvm.BUILD",
     sha256 = "13b96230c90025105ec9bdc914b1ccb6c4b319f68a44518ec4e86ef293f3dce8",
     strip_prefix = "zephyr-sdk-1.0.1",
     urls = ["https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v1.0.1/zephyr-sdk-1.0.1_linux-x86_64_llvm.tar.xz"],
@@ -128,14 +128,14 @@
 
 new_git_repository(
     name = "cmsis",
-    build_file = "//modules/cmsis:external.BUILD",
+    build_file = "@zephyr//modules/cmsis:external.BUILD",
     commit = "4b96cbb174678dcd3ca86e11e1f24bc5f8726da0",
     remote = "https://github.com/zephyrproject-rtos/cmsis.git",
 )
 
 new_git_repository(
     name = "cmsis_6",
-    build_file = "//modules/cmsis_6:external.BUILD",
+    build_file = "@zephyr//modules/cmsis_6:external.BUILD",
     commit = "30a859f44ef8ab4dc8f84b03ed586fd16ccf9d74",
     remote = "https://github.com/zephyrproject-rtos/CMSIS_6.git",
 )