mb/google/guybrush: add signed verstage and token

guybrush_psp_verstage.bin.signed: signed verstage for guybrush
based on 14205 firmware

monkey_island_shiraz.stkn: signing token for cezanne psp_verstage
(common for all MI platforms, b/178232750#comment21)

BUG=b:181277921
TEST=boot guybrush and check PSP boot mode

Change-Id: I5ce83b606fbdf8c8bc4c6e2539ba3f6a3b7a250c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/blobs/+/2987602
Tested-by: Kangheui Won <khwon@chromium.org>
Auto-Submit: Kangheui Won <khwon@chromium.org>
Reviewed-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Commit-Queue: Kangheui Won <khwon@chromium.org>
2 files changed