ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m

ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m

The Optiplex 9020m with Haswell-DT processor needs a quirk for the
headset jack at the front of the machine to be able to use microphones.

A quirk for this model was originally added in 3127899, but c77900e
removed it in favour of a more generic version.

Unfortunately, pin configurations can changed based on firmware/BIOS
versions, and the generic version doesn't have any effect on newer
versions of the machine/firmware anymore.

With help from David Henningsson <diwic@ubuntu.com>

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Tested-by: Bastien Nocera <hadess@hadess.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>