Add wmemcmp to Android.mk

Change-Id: I9dc96d72b2becdd31981b4d176a13358aef6dcb9
diff --git a/libc/Android.mk b/libc/Android.mk
index f700ca0..9d7dd3d 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -230,6 +230,7 @@
 	wchar/wcstok.c \
 	wchar/wcswidth.c \
 	wchar/wmemchr.c \
+	wchar/wmemcmp.c \
 	wchar/wmemcpy.c \
 	wchar/wmemmove.c \
 	wchar/wmemset.c \