ASoC: Intel: use common helpers to detect CPUs

We have duplicated code in multiple locations (atom, machine drivers,
SOF) to detect Baytrail, Cherrytrail and other SOCs. This is not very
elegant, and introduces dependencies on CONFIG_X86 that prevent
COMPILE_TEST from working.

Add common helpers to provide same functionality in a cleaner
way. This will also help support the DMI-based quirks being introduced
to handle SOF/SST autodetection.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>