soc/intel/cannonlake: Add initial dummy directory

soc/intel/cannonlake: Add initial dummy directory

Add Cannon Lake SoC boilerplate directory with:

 * SoC directory
 * Base Kconfig
 * Dummy cbmem.c

Change-Id: Ie28d8b56a1d1afcf1214ef734a08be6efcc8a931
Signed-off-by: Lijian Zhao <lijian.zhao@intel.com>
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/20061
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>