ASoC: SOF: Intel: hda-dsp: Add helper for setting DSP D0ix substate

Adding helper to implement setting dsp to d0i3 or d0i0 status, this will
be needed for driver D0ix support.

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191025224122.7718-5-pierre-louis.bossart@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>