pw_sync: Fix CMake yield_core target

Change-Id: Iaf56672b0eb0f73dfd252aaed3f47a76d85a5f2f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/79962
Reviewed-by: Wyatt Hepler <hepler@google.com>
Commit-Queue: Ewout van Bekkum <ewout@google.com>
Pigweed-Auto-Submit: Ewout van Bekkum <ewout@google.com>
diff --git a/pw_sync/CMakeLists.txt b/pw_sync/CMakeLists.txt
index fe365e4..312d6c2 100644
--- a/pw_sync/CMakeLists.txt
+++ b/pw_sync/CMakeLists.txt
@@ -154,7 +154,7 @@
     pw_sync.binary_semaphore_thread_notification_backend
 )
 
-pw_add_facade(pw_sync.yield_core
+pw_add_module_library(pw_sync.yield_core
   HEADERS
     public/pw_sync/yield_core.h
   PUBLIC_INCLUDES