sb/intel/common: Add common EC fw support

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>

src/southbridge/intel/common/firmware/Kconfig

@@ -115,6 +115,21 @@ config GBE_BIN_PATH
 	depends on HAVE_GBE_BIN
 	default "3rdparty/blobs/mainboard/$(MAINBOARDDIR)/gbe.bin"
 
+config HAVE_EC_BIN
+	bool "Add EC firmware"
+	depends on HAVE_IFD_BIN
+	help
+	  The embedded controller needs a firmware file.
+
+	  Select this if you are going to use the PCH integrated controller
+	  and have the EC firmware. EC firmware will be added to final image
+	  through ifdtool.
+
+config EC_BIN_PATH
+	string "Path to EC firmware"
+	depends on HAVE_EC_BIN
+	default "3rdparty/blobs/mainboard/$(MAINBOARDDIR)/ec.bin"
+
 ##### Fake IFD #####
 
 config BUILD_WITH_FAKE_IFD

src/southbridge/intel/common/firmware/Makefile.inc

@@ -74,6 +74,14 @@ ifeq ($(CONFIG_HAVE_GBE_BIN),y)
 		$(obj)/coreboot.pre
 	mv $(obj)/coreboot.pre.new $(obj)/coreboot.pre
 endif
+ifeq ($(CONFIG_HAVE_EC_BIN),y)
+	printf "    IFDTOOL    ec.bin -> coreboot.pre\n"
+	$(objutil)/ifdtool/ifdtool \
+		$(IFDTOOL_USE_CHIPSET) \
+		-i EC:$(CONFIG_EC_BIN_PATH) \
+		$(obj)/coreboot.pre
+	mv $(obj)/coreboot.pre.new $(obj)/coreboot.pre
+endif
 ifeq ($(CONFIG_LOCK_MANAGEMENT_ENGINE),y)
 	printf "    IFDTOOL    Locking Management Engine\n"
 	$(objutil)/ifdtool/ifdtool \