audio: move audio.h to system/core/include/system/audio.h

Change-Id: I523dfb361b1b3862cf8bc41c1691c607b2c815b0
Signed-off-by: Dima Zavin <dima@android.com>
diff --git a/include/hardware/audio_hal.h b/include/hardware/audio_hal.h
index 50675bd..c105370 100644
--- a/include/hardware/audio_hal.h
+++ b/include/hardware/audio_hal.h
@@ -26,7 +26,7 @@
 #include <cutils/bitops.h>
 
 #include <hardware/hardware.h>
-#include <hardware/audio.h>
+#include <system/audio.h>
 
 __BEGIN_DECLS