soundwire: export sdw_compute_slave_ports() function

Export sdw_compute_slave_ports() function to use it in another
soundwire manager module.
Move sdw_transport_data structure to bus header file to export
sdw_compute_slave_ports() function.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/lkml/20230201165944.3169125-1-Vijendar.Mukunda@amd.com
Link: https://lore.kernel.org/r/20230321050901.115439-2-Vijendar.Mukunda@amd.com


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