ALSA: HDA: Fix automute on Thinkpad L412/L512

BugLink: http://bugs.launchpad.net/bugs/707902



More Thinkpad machines with invalid SKU found, that disables
automute between speakers and headphones on these machines.

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