[ALSA] AC97 - renamed vendor/device to subvendor/subdevice where appropriate

AC97 Codec,ATIIXP driver,VIA82xx driver
To avoid confusion, the structure members vendor/device were renamed
to subvendor/subdevice, because we compare them with PCI subsystem vendor
and subsystem device.

Signed-off-by: Jaroslav Kysela <perex@suse.cz>