Add required .pm_ops to support suspend/resume on baytrail/cherrytrail
machines.

This .pm_ops is conditionally-added to avoid impacting the legacy
driver where power management is handled differently.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://lore.kernel.org/r/20200526203640.25980-5-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>