soundwire: intel: Add basic power management support

soundwire: intel: Add basic power management support

Implement suspend/resume capabilities (not runtime_pm for now)
The resume part is essentially a full-blown re-enumeration.

When S0ix is supported, we will select clock stop mode when the ACPI
target state is S0, and tear down the link for S3.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200721203723.18305-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>