[roll third_party/pigweed] pw_i2c: Add i2c rpc service

Service to read/write from arbitrary i2c devices. Useful for bringup and
debugging.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/155250

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 629081583deb171..d80eb6af2d30a1c
Roller-URL: https://ci.chromium.org/b/8775570116642625073
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I5790aa78fe7c0915efbdf109c3d8423084148635
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/155910
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 6290815..d80eb6a 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 629081583deb17187a1be40c2b61c863c5ad6b3c
+Subproject commit d80eb6af2d30a1c0fbdcc43b55e0b32eaf6b2f34