soundwire: Add compute_params callback

This callback allows masters to compute the bus parameters required.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190813083550.5877-2-srinivas.kandagatla@linaro.org


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