[pigweed] Roll 2 commits

bc671d3cc138147 pw_checksum: Improve commenting of CRC32 implement
18539d77fff9723 pw_build: Unify blob include paths

https://pigweed.googlesource.com/pigweed/pigweed
pigweed Rolled-Commits: c8a83ce57e4c790..bc671d3cc138147
Roller-URL: https://ci.chromium.org/b/8804997515679425713
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I0eac8fb5803e4d01968f3ea606e21707783a7f70
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/108012
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/pigweed b/pigweed
index c8a83ce..bc671d3 160000
--- a/pigweed
+++ b/pigweed
@@ -1 +1 @@
-Subproject commit c8a83ce57e4c790fc62c90404f1aef9ffa949925
+Subproject commit bc671d3cc13814776220aac858cd4d90e507887b