This time, the target is Cirrus codec.  Its parser is a subset of
generic parser, so we can migrate fully with it now.

The only tricky part is the handling of SPDIF automute.
Cirrus driver sets the SPDIF out plug over the headphone.  As a
workaround, set spec->gen.master_mute for toggling the headphone (and
other) mute.
Signed-off-by: Takashi Iwai <tiwai@suse.de>