snd-hda-intel: better Alienware M17x R3 quirk

I have been told that this way the rear headphone connector is
working as well; with model=alienware only laptop speakers work.
The subsystem of both controller and codec is 1028:0490.

Signed-off-by: Albert Pool <albertpool@solcon.nl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>