ALSA: hdspm - Add S/PDIF, XLR, WCK48 and ADAT-in controls for RME AIO cards

This commit adds the following ALSA controls:

   - S/PDIF Out Optical to switch S/PDIF Out from coaxial to optical
   - S/PDIF Out Professional to send the Pro bit in the output stream
   - ADAT-Internal to enable ADAT/TDIF Expansion Board (AEB/TEB)
   - XLR Breakout Cable if analogue I/O uses the XLR breakout cable
   - WCK48 to force WordClock to the 32-48kHz range (single speed) if
     the card is operating at higher frequencies

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