audio: Add support for two mic control

Change-Id: I0176b41b071577e9e55f5177ec1219d4e9aa91a2
diff --git a/audio/voice.c b/audio/voice.c
index f10d8ed..e59565a 100644
--- a/audio/voice.c
+++ b/audio/voice.c
@@ -244,6 +244,15 @@
     ril_set_call_volume(&session->ril, sound_type, volume);
 }
 
+bool voice_session_uses_twomic(struct voice_session *session)
+{
+    if (session->two_mic_disabled) {
+        return false;
+    }
+
+    return session->two_mic_control;
+}
+
 static void voice_session_wb_amr_callback(void *data, int enable)
 {
     struct audio_device *adev = (struct audio_device *)data;