[ALSA] hda-codec - Add ALC268 acer model

Added model=acer for ALC268 codec support.
The configuration is: headphone = 0x14, speaker = 0x15
needs hp-jack auto-detection.  The same routine as alc262-fujitsu model
is used.
Also, added the auto-muting routine for ALC268 model=toshiba.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>