[roll third_party/pigweed] pw_bluetooth: Remove unused LEMultiAcvtEnableCommand2 struct

Test: pw presubmit --step gn_emboss_build
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/148650

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 8311fbb3e3cb811..90921e0428798e3
Roller-URL: https://ci.chromium.org/b/8780190457161651297
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I5ba89ee03bf847ff893adbba04e5f9f942cc70ab
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/148714
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/third_party/pigweed b/third_party/pigweed
index 8311fbb..90921e0 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 8311fbb3e3cb811fa7a101987e9412591e4b35ed
+Subproject commit 90921e0428798e39c4b79bcaea59f48d71b883be