ALSA: usb-audio: add Edirol SD-90 PCM support

Add support for the 24-bit audio I/Os of the Edirol SD-90 interface.

Reported-any-tested-by: Jim Grusendorf <alsa-user@grusendorf.ca>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>