ALSA: hdspm - Add S/PDIF and WCK48 controls for RME RayDAT

This commit adds new ALSA controls to send single-speed WordClock and
S/PDIF-Professional on RME RayDAT cards.

Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>