ALSA: hda - Suppress auto-mute feature on some machines with ALC861

A few machines with ALC861 & co are reported not to work properly with
the auto-mute feature in software.  The auto-mute feature is implemented
in the hardware level, and the jack-detection never works with them.

Also, rename the fixup index as ALC861_FIXUP_* to follow the standard.

Signed-off-by: Takashi Iwai <tiwai@suse.de>