Add symbol AUDIO_PARAMETER_KEY_BT_SCO_WB

Change-Id: Ib2cfef74a57467cb01b5e0c44af335f53791e348
diff --git a/include/hardware/audio.h b/include/hardware/audio.h
index 6ba2544..b53cbff 100644
--- a/include/hardware/audio.h
+++ b/include/hardware/audio.h
@@ -97,6 +97,9 @@
 /* Screen state */
 #define AUDIO_PARAMETER_KEY_SCREEN_STATE "screen_state"
 
+/* Bluetooth SCO wideband */
+#define AUDIO_PARAMETER_KEY_BT_SCO_WB "bt_wbs"
+
 /**
  *  audio stream parameters
  */