ASoC: Intel: use standard interface for Atom machine drivers

Don't rely on internal Atom/SST-specific data structures, use
generic interface to let other drivers use the same machine drivers
as is, e.g. SOF to support BYT-CR devices

Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>