[roll] Roll fuchsia [magma][sys_driver_rust] Add Semaphore struct

Copy over the semaphore struct from an existing rust driver,
as this struct is likely to be the same in each GPU driver.

Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1627835
Original-Original-Revision: 1d4069b5a72263385b16f6d18ca788b073bc12de
GitOrigin-RevId: d0451e0c5d4a1682ed80abe7a4506ef9b1fe027e
Change-Id: I08825e7fae2531e36eceb819e0d369256877e643
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1629437
Cr-Commit-Position: refs/heads/main@{#193616}

stem

diff --git a/stem b/stem
index 9ca9f38..283edcb 100644
--- a/stem
+++ b/stem
@@ -8,6 +8,6 @@
             manifest="manifests/platform"
             root=""
             remote="https://fuchsia.googlesource.com/fuchsia"
-            revision="fbcd68659bf88ed55ee414a46b2136956b504886"/>
+            revision="1d4069b5a72263385b16f6d18ca788b073bc12de"/>
   </imports>
 </manifest>