ALSA: opti93x: set MC indirect registers base from PnP data

The PnP data on the OPTI931 and OPTI933 contains io port
range for the MC indirect registers. Use the PnP range
instead of hardwired value 0xE0E.

Also, request region of MC indirect registers so it is
marked as used to other drivers (this was missing previously).

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>