Add default build with linux device layer (#1568)

* Add default build with linux device layer

* Rename linux_embedded to linux_x64_gcc_embedded for consistency
diff --git a/BUILD.gn b/BUILD.gn
index d389987..0cb5665 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -104,8 +104,11 @@
     # Enable building chip with gcc.
     enable_host_gcc_build = enable_default_builds
 
-    # Build building chip with gcc & mbedtls.
-    enable_host_gcc_mbdtls_build = enable_default_builds
+    # Enable building chip with gcc & mbedtls.
+    enable_host_gcc_mbedtls_build = enable_default_builds
+
+    # Enable building chip for linux embedded.
+    enable_linux_embedded_build = enable_default_builds && host_os == "linux"
 
     # Build the chip-tool example.
     enable_standalone_chip_tool_build = enable_default_builds
@@ -132,6 +135,13 @@
     toolchain = "${chip_root}/config/mbedtls/toolchain:${host_os}_${host_cpu}_gcc_mbedtls"
   }
 
+  if (host_os == "linux") {
+    chip_build("linux_embedded") {
+      toolchain =
+          "${chip_root}/config/linux/toolchain:linux_${host_cpu}_gcc_embedded"
+    }
+  }
+
   standalone_toolchain = "${chip_root}/config/standalone/toolchain:standalone"
 
   group("standalone_chip_tool") {
@@ -162,9 +172,12 @@
     if (enable_host_gcc_build) {
       deps += [ ":all_host_gcc" ]
     }
-    if (enable_host_gcc_mbdtls_build) {
+    if (enable_host_gcc_mbedtls_build) {
       deps += [ ":all_host_gcc_mbedtls" ]
     }
+    if (enable_linux_embedded_build) {
+      deps += [ ":all_linux_embedded" ]
+    }
     if (enable_standalone_chip_tool_build) {
       deps += [ ":standalone_chip_tool" ]
     }
@@ -188,9 +201,12 @@
       if (enable_host_gcc_build) {
         deps += [ ":check_host_gcc" ]
       }
-      if (enable_host_gcc_mbdtls_build) {
+      if (enable_host_gcc_mbedtls_build) {
         deps += [ ":check_host_gcc_mbedtls" ]
       }
+      if (enable_linux_embedded_build) {
+        deps += [ ":check_linux_embedded" ]
+      }
     }
   }
 }