Separate audio stack and SDL

Change-Id: Ibf3d08172807bca7dc46d70bf51d5eadaed4372b
diff --git a/Makefile.android b/Makefile.android
index 38ad685..0773e39 100644
--- a/Makefile.android
+++ b/Makefile.android
@@ -324,7 +324,7 @@
 
 # determine AUDIO sources based on current configuration
 #
-AUDIO_SOURCES := audio.c noaudio.c wavaudio.c sdlaudio.c wavcapture.c mixeng.c
+AUDIO_SOURCES := audio.c noaudio.c wavaudio.c wavcapture.c mixeng.c
 AUDIO_CFLAGS  := -I$(LOCAL_PATH)/audio -DHAS_AUDIO
 AUDIO_LDLIBS  :=