audio: add support for routing to/from voice TX/RX paths

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

Bug: 15520724.

Change-Id: Ia4a4428001ea06f7c7b213db861ec281ebd25174
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index 62bc100..8940f5b 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -75,6 +75,10 @@
     USECASE_INCALL_REC_UPLINK,
     USECASE_INCALL_REC_DOWNLINK,
     USECASE_INCALL_REC_UPLINK_AND_DOWNLINK,
+
+    USECASE_AUDIO_PLAYBACK_AFE_PROXY,
+    USECASE_AUDIO_RECORD_AFE_PROXY,
+
     AUDIO_USECASE_MAX
 } audio_usecase_t;
 
@@ -154,7 +158,7 @@
     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;
@@ -191,6 +195,8 @@
     audio_mode_t mode;
     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;