[roll third_party/pigweed] pw_hdlc: Remove unused targets

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/188226

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 43ce44233375111..b2f23b4e8480985
Roller-URL: https://ci.chromium.org/b/8758525532449916609
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I49cf97dc374df0e3c4560124939350f3de443a81
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/188370
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 43ce442..b2f23b4 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 43ce442333751114c7edfdc1d5d8025f5920d051
+Subproject commit b2f23b4e848098589642a529832bc89117d16bb3