soundwire: master: add runtime pm support

We need to enable runtime_pm on master device with generic helpers,
so that a Slave-initiated wake is propagated to the bus parent.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-6-yung-chuan.liao@linux.intel.com


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