ASoC: intel: add support for specifying PCM format

With this machines can configure the PCM format applied on SSP port using
the set_fmt API

Signed-off-by: Praveen Diwakar <praveen.diwakar@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>