google/trogdor: Add new variant Marzipan

This patch adds a new variant called Marzipan that is identical to Lazor
for now.

BUG=b:182181519,b:182018606
BRANCH=master
TEST=make

Change-Id: I92b667c63b0a06255d1e9511d7486293d8b4426a
Signed-off-by: Kevin Chiu <kevin.chiu@quantatw.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51618
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

Documentation/security/vboot/list_vboot.md

@@ -156,6 +156,7 @@
 - Coachz
 - Homestar
 - Lazor
+- Marzipan
 - Pompom
 - Trogdor
 - Veyron_Jaq (Haier Chromebook 11)