hal: add support to send/receive voice call TX/RX audio

Add support for routing voice calls to devices in other audio
HALs by allowing playback and capture to/from AFE proxy

Change-Id: I2c6a1ddec072e1d5f1a8b7ded874e9c082a7b810
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index a810674..d05f743 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -111,6 +111,10 @@
 
     USECASE_AUDIO_SPKR_CALIB_RX,
     USECASE_AUDIO_SPKR_CALIB_TX,
+
+    USECASE_AUDIO_PLAYBACK_AFE_PROXY,
+    USECASE_AUDIO_RECORD_AFE_PROXY,
+
     AUDIO_USECASE_MAX
 };
 
@@ -200,7 +204,7 @@
     int standby;
     int source;
     int pcm_device_id;
-    int device;
+    audio_devices_t device;
     audio_channel_mask_t channel_mask;
     audio_usecase_t usecase;
     bool enable_aec;
@@ -266,6 +270,8 @@
     audio_devices_t out_device;
     struct stream_in *active_input;
     struct stream_out *primary_output;
+    struct stream_out *voice_tx_output;
+    struct stream_out *current_call_output;
     bool bluetooth_nrec;
     bool screen_off;
     int *snd_dev_ref_cnt;