ART: Move to using locks.h instead of mutex.h

When only annotating lock requirements, use locks.h.

Bug: 119869270
Test: mmma art
Change-Id: I1608b03254712feff0072ebad012c3af0cc3dda4
diff --git a/runtime/read_barrier.h b/runtime/read_barrier.h
index 0741da6..3b89377 100644
--- a/runtime/read_barrier.h
+++ b/runtime/read_barrier.h
@@ -19,8 +19,8 @@
 
 #include <android-base/logging.h>
 
+#include "base/locks.h"
 #include "base/macros.h"
-#include "base/mutex.h"
 #include "base/runtime_debug.h"
 #include "gc_root.h"
 #include "jni.h"