vboot: Separate vboot from chromeos

VBOOT_VERIFY_FIRMWARE should be independent of CHROMEOS. This allows use
of verified boot library without having to stick to CHROMEOS.

BUG=chrome-os-partner:55639

Change-Id: Ia2c328712caedd230ab295b8a613e3c1ed1532d9
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/15867
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

src/soc/intel/broadwell/igd.c

@@ -30,7 +30,7 @@
 #include <soc/ramstage.h>
 #include <soc/systemagent.h>
 #include <soc/intel/broadwell/chip.h>
-#include <vendorcode/google/chromeos/chromeos.h>
+#include <vboot/vbnv.h>
 
 #define GT_RETRY 		1000
 #define GT_CDCLK_337		0