[roll third_party/pigweed] pw_sensor: Add module stub

This change provides the baseline for building the sensor framework.

Original-Bug: b/293466822
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/202911

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: e79414ec1071a38..d8c170bbb03c587
Roller-URL: https://ci.chromium.org/b/8750921331094089777
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I2421306e8774a9e41661ddd4bb33344cc1cb1853
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/203050
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 e79414e..d8c170b 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit e79414ec1071a382b92e56601bb569439b5d3125
+Subproject commit d8c170bbb03c5872ae3cdfd0da2372c828222275