Without this patch, the headset mic will not work on this machine.

BugLink: https://bugs.launchpad.net/bugs/1476987Signed-off-by: NDavid Henningsson <david.henningsson@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>