ALSA: usb-audio: UAC2: auto clock selection module param

Add a module param to disable auto clock selection.
This is provided for users that expect the audio stream to
fail when the clock source is invalid (e.g., the word clock
was unintentionally disconnected).

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/usbaudio.h

@@ -56,6 +56,7 @@ struct snd_usb_audio {
 
 	int setup;			/* from the 'device_setup' module param */
 	int nrpacks;			/* from the 'nrpacks' module param */
+	bool autoclock;			/* from the 'autoclock' module param */
 
 	struct usb_host_interface *ctrl_intf;	/* the audio control interface */
 };