[roll] Roll fuchsia [audio] Add SignalProcessing protocol

Partial API definition, see also go/tq-audio-drivers-topologies.

Original-Bug: 64877
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/607521
Original-Revision: 4eb8a714e6ed609cba13f84fde639f77808e9f2d
GitOrigin-RevId: 70c17b94dd8342375819eaa3e7d9d624f44358bc
Change-Id: I33e44cb18f3d92d4b393e010f73953b9774e2f5d
diff --git a/stem b/stem
index 5d97ac0..6aaecb3 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="66f6b003ec7a93d6a44677b7a091b540113ae7bf"/>
+             revision="4eb8a714e6ed609cba13f84fde639f77808e9f2d"/>
   </projects>
   <hooks>
     <hook name="install-environment"