ALSA: HDA: Refactor some redundant code for Conexant 5066/205xx

Four very similar procedures - one for each model - now
refactored into one. This isn't all duplicated code, but a step
in the right direction.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>