[roll pigweed] pw_software_update: Clean up TODOs

Remove obsolete and no longer relevant TODOs and re-direct remaining
TODOs to new bug.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/100480

https://pigweed.googlesource.com/pigweed/pigweed
pigweed Rolled-Commits: 0daafccb9b75618..e22c6ffa2374ee9
Roller-URL: https://ci.chromium.org/b/8809981306507774241
Cq-Cl-Tag: roller-builder:pigweed-zephyr-roller
Cq-Cl-Tag: roller-bid:8809981306507774241
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: If7ea32d6cf53144f5cebe1be205a055e8b923515
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/100484
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pigweed b/pigweed
index 0daafcc..e22c6ff 160000
--- a/pigweed
+++ b/pigweed
@@ -1 +1 @@
-Subproject commit 0daafccb9b756187df69d848801b404e89f5b4de
+Subproject commit e22c6ffa2374ee987ab0bcbf8fd7af0f7e7186c6