ALSA: usb-audio: Update DSD support quirks for Oppo and Rotel

Oppo has issued firmware updates that change alt setting used for DSD
support. However, these devices seem to support auto-detection, so
support is moved from explicit whitelisting to auto-detection.

Also Rotel devices have USB interfaces that support DSD with
auto-detection.

Signed-off-by: Jussi Laako <jussi@sonarnerd.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>