[roll] Roll fuchsia [kernel][timer] Clarify that Timers aren't bound to a given CPU

Update the Timer docs to clarify that Timers aren't permanently bound
to a given.

Original-Bug: 392888672
Original-Bug: 410034543
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1250728
Original-Revision: cf28acce4f0827bdfc83556a3cb56a928119ddf0
GitOrigin-RevId: 191438977c82c8b72c70f5110802e821bb6dcce0
Change-Id: I432c31e8fd433d665f53be676be33ac0f9dc7d1d
diff --git a/stem b/stem
index bc8a74c..374dde7 100644
--- a/stem
+++ b/stem
@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="4ce44ec1f18f6b7e764051e88f8cbf929b3a3cac"
+             revision="cf28acce4f0827bdfc83556a3cb56a928119ddf0"
              />
   </projects>
   <hooks>