This guards code accessing the vboot context which does not exist if vboot starts after romstage. Change-Id: I2a38daa00d6d18df9c5e22858530814e23bb3e00 Signed-off-by: Arthur Heymans <arthur@aheymans.xyz> Reviewed-on: https://review.coreboot.org/c/coreboot/+/52157 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Frans Hendriks <fhendriks@eltan.com>