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/msm8974/platform.h b/hal/msm8974/platform.h
index be138c0..8bf9648 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -164,6 +164,7 @@
     SND_DEVICE_OUT_BUS_NAV,
     SND_DEVICE_OUT_BUS_PHN,
     SND_DEVICE_OUT_BUS_RSE,
+    SND_DEVICE_OUT_CALL_PROXY,
     SND_DEVICE_OUT_END,
 
     /*
@@ -307,6 +308,7 @@
     SND_DEVICE_IN_HANDSET_QMIC_AND_EC_REF_LOOPBACK,
     SND_DEVICE_IN_HANDSET_6MIC_AND_EC_REF_LOOPBACK,
     SND_DEVICE_IN_HANDSET_8MIC_AND_EC_REF_LOOPBACK,
+    SND_DEVICE_IN_CALL_PROXY,
     SND_DEVICE_IN_END,
 
     SND_DEVICE_MAX = SND_DEVICE_IN_END,
@@ -332,6 +334,7 @@
     DISP_PORT_RX_BACKEND,
     DISP_PORT1_RX_BACKEND,
     USB_AUDIO_RX_BACKEND,
+    CALL_PROXY_RX_BACKEND,
     MAX_RX_CODEC_BACKENDS = USB_AUDIO_RX_BACKEND,
     /* TX BE follows RX BE */
     SLIMBUS_0_TX,
@@ -342,6 +345,7 @@
     HDMI_TX_BACKEND,
     HDMI_ARC_TX_BACKEND,
     HEADSET_TX_BACKEND,
+    CALL_PROXY_TX_BACKEND,
     MAX_CODEC_BACKENDS
 };