ALSA: hda/realtek: apply ALC891 headset fixup to one Dell machine

commit 4b4e0e32e4b09274dbc9d173016c1a026f44608c upstream.

Without this patch, the headset-mic and headphone-mic don't work.

Cc: <stable@vger.kernel.org>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>