ALSA: hda - Add a fixup for ASUS N76VZ

ASUS N76VZ needs the same fixup as N56VZ for supporting the boost
speaker.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=846529
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>