ALSA: hda - Fix internal mic for Lenovo Ideapad U300s

ALSA: hda - Fix internal mic for Lenovo Ideapad U300s

commit 18dcd3044e4c4b3ab6341c98e8d0e81e0d58d5e3 upstream.

The internal mic input is phase inverted on one channel.
To avoid people in userspace summing the channels together
and get zero result, use a separate mixer control for the
inverted channel.

BugLink: https://bugs.launchpad.net/bugs/903853
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2:
 - Adjust context
 - Change both invocations of apply_pin_fixup()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>