ALSA: hda - Add a fixup for Gateway LT27

commit 1801928e0f99d94c55e33c584c5eb2ff5e246ee6 upstream.

Gateway LT27 needs a fixup for the inverted digital mic.

Reported-by: "Nathanael D. Noblet" <nathanael@gnat.ca>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>