hal: add support for callscreening.
handle newly added callscreening mode, provide support for device selection
as per this new mode.
Change-Id: I3c57c9edd38cf4347d11c871e1878a4536936edc
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index ce82145..cc9e602 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -612,6 +612,7 @@
pthread_mutex_t cal_lock;
struct mixer *mixer;
audio_mode_t mode;
+ audio_mode_t prev_mode;
audio_devices_t out_device;
struct stream_out *primary_output;
struct stream_out *voice_tx_output;