vboot/ui: Implement firmware log screen

Implement firmware log screen which can be accessed from advanced
options menu.

The screen displays a snapshot for the firmware log using the same
layout of debug info screen.

BRANCH=puff, zork
BUG=b:146399181, b:146105976
    make clean && make runtests
TEST=USE="menu_ui" emerge-puff depthcharge
TEST=USE="menu_ui" emerge-zork depthcharge
TEST=select "advanced options",
     and navigate to firmware log screen

Cq-Depend: chromium:2334490
Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
Change-Id: I3cb5800d71925aa20ca4d5636172885e23fd0099
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2328241
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
4 files changed