soundwire: bus: simplify by using local slave->prop

The sdw_initialize_slave() function stores 'slave->prop' as local 'prop'
variable, so use it in all applicable places to make code a bit simpler.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20240620091046.12426-1-krzysztof.kozlowski@linaro.org


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