Add support to the Intel common firmware Kconfig and Makefile.inc to allow the embedded controller (EC) blob to be added to the final binary through ifdtool. TEST=Add ec.bin and enable in config, build is successful. Change-Id: Ib14732b4d263dde4770bf26b055c005de2540338 Signed-off-by: Lijian Zhao <lijian.zhao@intel.com> Reviewed-on: https://review.coreboot.org/19719 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com> Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>