[roll third_party/pigweed] pw_system: Add arm_none_eabi_gcc_support

Add this library as to the `pw_build_LINK_DEPS` to resolve certain build
warnings.

Original-Fixed: b/292283741
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/158730

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: eb6d39c3e24cfc0..7ef95e5adb78594
Roller-URL: https://ci.chromium.org/b/8770047328664183249
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Iebf4f88786131bc6cb890897b9304abdef1fbab1
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/170819
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index eb6d39c..7ef95e5 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit eb6d39c3e24cfc08cf8d072390dd63f62e4979cd
+Subproject commit 7ef95e5adb78594958f9c16b0755bc52a8a1c10d