ALSA: intel8x0: Fix default inaudible sound on Gateway M520

commit 27c3afe6e1cf129faac90405121203962da08ff4 upstream.

BugLink: https://bugs.launchpad.net/bugs/930842
The reporter states that audio is inaudible by default without muting
'External Amplifier'. Add a quirk to handle his SSID so that changing
the control is not necessary.

Reported-and-tested-by: Benjamin Carlson <elderbubba0810@gmail.com>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>