ALSA: usb-audio: Move interface setup delay into quirk_flags

Yet another delay is applied at switching the interface.  This can be
moved to quirk_flags, too.

Link: https://lore.kernel.org/r/20210729073855.19043-10-tiwai@suse.de


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