[roll third_party/pigweed] pw_sync_threadx: Adjust ISL enum to make it bss eligible

Adjusts an enum's values to ensure that a value of 0 is used in the
constexpr constructor to ensure that the object is bss eligible
instead of requiring placement in data.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/55027

third_party/pigweed Rolled-Commits: 68ef2a59c2ccaba..e4ed1011d2e1113
Roller-URL: https://ci.chromium.org/b/8840411259259685568
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8840411259259685568
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Id750f8e2b96ac0d15bf7dd3059b1b1c8bf1dfd71
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/55052
Reviewed-by: 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 68ef2a5..e4ed101 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 68ef2a59c2ccabaef5f3662d5cac56f0f3c85942
+Subproject commit e4ed1011d2e111381a8279d53a0c9c14f8f6a5b8