ASoC: cs35l56: Read firmware uuid from a device property instead of _SUB

ASoC: cs35l56: Read firmware uuid from a device property instead of _SUB

Use a device property "cirrus,firmware-uid" to get the unique firmware
identifier instead of using ACPI _SUB. There aren't any products that use
_SUB.

There will not usually be a _SUB in Soundwire nodes. The ACPI can use a
_DSD section for custom properties.

There is also a need to support instantiating this driver using software
nodes. This is for systems where the CS35L56 is a back-end device and the
ACPI refers only to the front-end audio device - there will not be any ACPI
references to CS35L56.

Fixes: e49611252900 ("ASoC: cs35l56: Add driver for Cirrus Logic CS35L56")
Signed-off-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230817112712.16637-2-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>