This commit allows this driver to support all of models which Yamaha produced
with DM1000/BeBoB. They are:
 - GO44
 - GO46

This commit adds Yamaha specific operations. To get source of clock, AV/C Audio
Subunit command is used.

I note that their appearances are similar to some models of TerraTec; 'Go44' is
similar to 'PHASE 24 FW' and 'GO46' is similar to 'PHASE X24 FW'. But their
combination of Audio/Music subunits is a bit different.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>