ALSA: usb-audio: Exclude Scarlett 18i20 1st Gen from SKIP_IFACE_SETUP

ALSA: usb-audio: Exclude Scarlett 18i20 1st Gen from SKIP_IFACE_SETUP

Same issue as the other 1st Gen Scarletts: QUIRK_FLAG_SKIP_IFACE_SETUP
causes distorted audio on the Scarlett 18i20 1st Gen (1235:800c).

Fixes: 38c322068a26 ("ALSA: usb-audio: Add QUIRK_FLAG_SKIP_IFACE_SETUP")
Reported-by: tucktuckg00se [https://github.com/geoffreybennett/linux-fcp/issues/54]
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://patch.msgid.link/ad0ozNnkcFrcjVQz@m.b4.vu
Signed-off-by: Takashi Iwai <tiwai@suse.de>