soundwire: intel: add prototype for WAKEEN interrupt processing

In ClockStop mode, the PCI device will be notified of a wake, which
will be handled from an interrupt thread.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191212014507.28050-10-pierre-louis.bossart@linux.intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>