ASoC: Intel: sst-acpi: Add support for multiple machine drivers per platform

Initial implementation of this driver focused only matching SST ACPI ID
with single machine driver and same firmware file per platform. It was known
restriction to be improved incrementally.

This patch is now changing this that SST ACPI ID refers purely to platform
specific data which refers to machine drivers on this platform, not vice
versa.

Matching machine driver is found by looking at ACPI ID which would best
match with the driver. Typically this would be the ACPI ID of audio codec
but is not tied to it.

This patch also changes that DSP firmware name is machine not platform
specific.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>