ASoC: Intel: Skylake: Update channel map based on runtime params

Default channel map is set for 2 channels. Fix the channel map
based on runtime params to support multichannel.

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>