ALSA: atiixp: Specify codec for Foxconn RC4107MA-RS2

BugLink: https://bugs.launchpad.net/ubuntu/+bug/498863

This mainboard needs ac97_codec=0.

Cc: stable@kernel.org
Tested-by: Apoorv Parle <apparle@yahoo.co.in>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>