[third_party/pigweed] Roll 5 commits

7cffdd83bfd413c pw_thread: Follow Soong guidance
7682e4abe456481 pw_allocator: Add allocation detail storage to Tra
ebcc8c717f3980d pw_channel: Add loopback channel
72a1d6f484ecbd1 pw_toolchain: Remove unusued source set
16d3c47ab5a6d45 pw_status: Add StatusWithSize::size_or

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 55b88ef80fc2403..7cffdd83bfd413c
Roller-URL: https://ci.chromium.org/b/8752371766664827249
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I92b996d3459a00cbfd5b540d64db04a5218633df
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/200153
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 55b88ef..7cffdd8 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 55b88ef80fc2403fc55642ead01b2a71cd0e7448
+Subproject commit 7cffdd83bfd413cd000322d13d57443306771090