Remove dependency on audio_* location

Change-Id: I4bc66115fcb9ba22b057bd72db3f561dcb18a0d8
diff --git a/voip/jni/rtp/Android.mk b/voip/jni/rtp/Android.mk
index 0815294..49b711d 100644
--- a/voip/jni/rtp/Android.mk
+++ b/voip/jni/rtp/Android.mk
@@ -50,7 +50,7 @@
 	frameworks/base/media/libstagefright/codecs/amrnb/enc/src \
 	frameworks/base/media/libstagefright/codecs/amrnb/dec/include \
 	frameworks/base/media/libstagefright/codecs/amrnb/dec/src \
-	system/media/audio_effects/include
+	$(call include-path-for, audio-effects)
 
 LOCAL_CFLAGS += -fvisibility=hidden