ALSA: hda - Add quirk for Acer AX1700-U3700A

Force model=auto for Acer AX1700-U3700A with ALC888 codec.
Since Acer devices are handlded as model=acer as default, the auto
parsing has to be specified explicitly.
(Maybe it's better rather to remove this default model=acer handling,
 though.)

Signed-off-by: Takashi Iwai <tiwai@suse.de>