soundwire: Add helpers for ports operations

Add helpers to configure, prepare, enable, disable and
de-prepare ports.

Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Signed-off-by: Shreyas NC <shreyas.nc@intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>