This is a backport for stable. The original commit SHA is
338cae56.

On this machine, DAC on node 0x03 seems to give mono output.

Also, it needs additional patches for headset mic support.
It supports CTIA style headsets only.

Alsa-info available at the bug link below.

BugLink: https://bugs.launchpad.net/bugs/1236228Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>