Add Mips architecture to system/core/include

Change-Id: Ief7bdbd8d09cabe3f11f3ed47a932a7faa81cad9
diff --git a/include/cutils/atomic-inline.h b/include/cutils/atomic-inline.h
index 49f3e70..64cdd9d 100644
--- a/include/cutils/atomic-inline.h
+++ b/include/cutils/atomic-inline.h
@@ -49,6 +49,8 @@
 #include <cutils/atomic-x86.h>
 #elif defined(__sh__)
 /* implementation is in atomic-android-sh.c */
+#elif defined(__mips__)
+#include <cutils/atomic-mips.h>
 #else
 #error atomic operations are unsupported
 #endif