ALSA: HDA: Add quirk for Lenovo U350

Add model=asus quirk for Lenovo Ideapad U350 to make internal mic
work correctly.

Cc: stable@kernel.org (2.6.38+)
BugLink: http://bugs.launchpad.net/bugs/751681


Reported-by: Kent Baxley <kent.baxley@canonical.com>
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>