[MIPS] Enable futex support

Change-Id: I4095d889229fe1b96f7b276d7952b3578c8fcd6d
diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index ee37388..3e05b10 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -32,7 +32,7 @@
 #if defined(__APPLE__)
 #define ART_USE_FUTEXES 0
 #else
-#define ART_USE_FUTEXES !defined(__mips__)
+#define ART_USE_FUTEXES 1
 #endif
 
 // Currently Darwin doesn't support locks with timeouts.