audio: Add voice call wideband support

Change-Id: Idf6725aaaf906109ce973a8109b7c252a997dead
diff --git a/audio/voice.h b/audio/voice.h
index c63cd26..352e839 100644
--- a/audio/voice.h
+++ b/audio/voice.h
@@ -41,6 +41,7 @@
 void set_voice_session_audio_path(struct voice_session *session);
 
 bool voice_session_uses_twomic(struct voice_session *session);
+bool voice_session_uses_wideband(struct voice_session *session);
 
 struct voice_session *voice_session_init(struct audio_device *adev);
 void voice_session_deinit(struct voice_session *s);