ALSA: usb-audio: Add DSD support for Accuphase DAC-60

Accuphase DAC-60 option card supports native DSD up to DSD256,
but doesn't have support for auto-detection. Explicitly enable
DSD support for the correct altsetting.

Signed-off-by: Jussi Laako <jussi@sonarnerd.net>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20221108221241.1220878-1-jussi@sonarnerd.net
Signed-off-by: Takashi Iwai <tiwai@suse.de>