Pull in commit adding signed verstage files for Google mainboards zork, guybrush, and skyrim. Change-Id: Ia3024622a622285b7b2a1f4eef88cf0e2927424e Signed-off-by: Matt DeVillier <matt.devillier@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/76946 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>