ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware

When loading firmware, wm_adsp uses a number of parameters to
determine the path of the firmware and tuning files to load.
One of these parameters is system_name.
Add support in cs35l41 to read this system name from the ACPI
_SUB ID in order to uniquely identify the firmware and tuning
mapped to a particular system.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220707151037.3901050-3-sbinding@opensource.cirrus.com


Signed-off-by: Mark Brown <broonie@kernel.org>