soundwire: export helpers to find row and column values

soundwire: export helpers to find row and column values

Add a prefix for common tables and export 2 helpers to set the frame
shapes based on row/col values.

These changes simplify bandwidth allocation algorithms as well as the
Cadence parts which all need to convert from frame shape to indices
used by the standard. These helpers are used in the following patch.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190806005522.22642-6-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>