mac80211: add back lost debugfs files

Somehow these files were never present or lost, but the code
is there and they seem somewhat useful, so add them back.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

path: root/sound/usb/stream.h

#ifndef __USBAUDIO_STREAM_H
#define __USBAUDIO_STREAM_H

int snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
				  int iface_no);

int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
			     int stream,
			     struct audioformat *fp);

#endif /* __USBAUDIO_STREAM_H */