ASoC: Intel: Skylake: cleanup before moving ACPI tables

There is no need to deal with DMICs if the DSP is not present and
there is no ACPI machine ID found.

Simplify before moving these ACPI tables to sound/soc/intel/common

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>