SM8450 machine driver code can be reused across multiple Qualcomm SoCs,
At least another 2 of them for now (SM8450 and SC8250XP).

Move some of the common SoundWire stream specific code to common file
so that other drivers can use it instead of duplication.

This patch is to prepare the common driver to be able to add new SoCs support
with less dupication.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220916132427.1845-5-srinivas.kandagatla@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>