ALSA: hda - Add quirk for external mic on Lifebook U904

commit 2041d56464a067461d7cc21734a0f024587ed2ff upstream.

According to the bug reporter (Данило Шеган), the external mic
starts to work and has proper jack detection if only pin 0x19
is marked properly as an external headset mic.

AlsaInfo at https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1328587/+attachment/4128991/+files/AlsaInfo.txt

BugLink: https://bugs.launchpad.net/bugs/1328587
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2:
 - s/struct hda_pintbl/struct alc_pincfg/
 - s/HDA_FIXUP_PINS/ALC_FIXUP_PINS/
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc sound/pci/hda/patch_realtek.c
Simple merge