soundwire: bus: add PM/no-PM versions of read/write functions

Add support for pm_runtime with the appropriate error checks for
sdw_write/read functions, e.g. when pm_runtime is not supported.

Also expose internal functions without pm_runtime support, which are
required to perform any sort of suspend/resume operation, as well as
any enumeration tasks.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-5-pierre-louis.bossart@linux.intel.com


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