ALSA: usb-audio: Move clock setup quirk into quirk_flags

There are a couple of device-specific quirks in the clock setup code,
and those can be moved gracefully to quirk_flags, too.

Link: https://lore.kernel.org/r/20210729073855.19043-7-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>