android: set the HAVE_VISIBILITY define

... in order to limit the exported symbols only to the required ones.
Both compilers used with Android (GCC and LLVM) support this, so set it
unconditionally.

Cc: Chih-Wei Huang <cwhuang@linux.org.tw>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

Android.mk

@@ -39,6 +39,7 @@ LOCAL_C_INCLUDES := \
 	$(LOCAL_PATH)/include/drm
 
 LOCAL_CFLAGS := \
+	-DHAVE_VISIBILITY=1 \
 	-DHAVE_LIBDRM_ATOMIC_PRIMITIVES=1
 
 include $(BUILD_SHARED_LIBRARY)