skylake/mainboard: Define mainboard hook in bootblock

Move mainboard post console init functionality (google_chrome_ec_init &
early_gpio programming) from verstage to bootblock.

Add chromeos-ec support in bootblock

BUG=chrome-os-partner:55357
BRANCH=none
TEST=Built and boot kunimitsu till POST code 0x34

Change-Id: I1b912985a0234d103dcf025b1a88094e639d197d
Signed-off-by: Barnali Sarkar <barnali.sarkar@intel.com>
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/15786
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 24116e9..5f708a6 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -201,6 +201,7 @@
 $(call src-to-obj,verstage,$(dir)/fmap.c) : $(obj)/fmap_config.h
 $(call src-to-obj,postcar,$(dir)/fmap.c) : $(obj)/fmap_config.h
 
+bootblock-y += bootmode.c
 romstage-y += bootmode.c
 ramstage-y += bootmode.c
 verstage-y += bootmode.c