[third_party/pigweed] Roll 2 commits

67c87c7fe8f129c build: Mark linux-only Bazel build targets
86d80d6921dffc8 pw_base64: Doxygenify MaxDecodedSize()

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: e171f29b7d61f05..67c87c7fe8f129c
Roller-URL: https://ci.chromium.org/b/8774575444356592577
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ie5b2fbf39ad8adfc9d3c231e6fc93815beee5e6e
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/159313
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 e171f29..67c87c7 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit e171f29b7d61f057fd5d3b0e3acf698d0692ce80
+Subproject commit 67c87c7fe8f129cf825507ca88064fe3ae9a707a