soundwire: add definitions for 1.2 spec

Add definitions for register offsets and bit fields from the MIPI
SoundWire 1.2 specification (available to MIPI members at
https://members.mipi.org/wg/All-Members/document/download/78371

)

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200608205436.2402-2-yung-chuan.liao@linux.intel.com


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