ALSA: doc: Add the description of quirk_flags option for snd-usb-audio

Just briefly described about the new option.

Link: https://lore.kernel.org/r/20210729074404.19728-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2021-07-29 09:44:04 +02:00
commit a39978ed6d