soundwire: add helper macros for devID fields

Move bit extractors to macros, so that the definitions can be used by
other drivers parsing the MIPI definitions extracted from firmware
tables (ACPI or DT).

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200225170041.23644-4-pierre-louis.bossart@linux.intel.com


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