ALSA: HDA: Sigmatel: work around incorrect master muting

The HDA specification does not allow for a codec to mute itself just
because the volume is reduced, so _of course_ somebody had to go and do
it.  This wouldn'\''t hurt too much when the volume is adjusted by hand,
but programs like PA that try to set the volume automatically could
inadvertently mute the output.

To work around this, change the TLV dB information for the Master volume
on all Sigmatel HDA codecs to indicate the the minimal volume setting
actually mutes.

Reported-by: Colin Guthrie <gmane@colin.guthr.ie>
Reported-by: "Alexander E. Patrakov" <patrakov@gmail.com>
Tested-by: Colin Guthrie <cguthrie@mandriva.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>