ALSA: hda - Add mute LED control for Lenovo Ideapad Z560

Lenovo Ideapad Z560 has a mute LED that is controlled via EAPD pin
0x1b on CX20585 codec.  (EAPD bit on corresponds to mute LED on.)
The machine doesn't need other EAPD, so the fixup concentrates on
controlling EAPD 0x1b following the vmaster state (but inversely).

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=665315
Reported-by: Szymon Kowalczyk <fazerxlo@o2.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>