[third_party/pigweed] Roll 2 commits

76881ff0c7773f0 pw_bluetooth: Duplicate Emboss vendor commands int
c3ba992d0773824 pw_i2c_linux: Add Linux I2C backend

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: e4754e73b724bcb..76881ff0c7773f0
Roller-URL: https://ci.chromium.org/b/8778933112387221889
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I8c0e3df7881a17be3ad5c52d92bb13faf81ae1c8
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/150932
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index e4754e7..76881ff 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit e4754e73b724bcbc82336003a43bdd87f162b8b8
+Subproject commit 76881ff0c7773f05df593f052eb1a0e3f9aa8f93