ASoC: hdac_hdmi: Register chmap controls and ops

With this patch, chmap controls are created and user space can
set the channel map.

Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>