ASoC: Intel: cht_bsw_rt5645: add Baytrail MCLK support

The existing code assumes a 19.2 MHz MCLK as the default
hardware configuration. This is valid for CherryTrail but
not for Baytrail.

Add explicit MCLK configuration to set the 19.2 clock on/off
depending on DAPM events.

This is a prerequisite step to enable devices with Baytrail
and RT5645 such as Asus X205TA

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>