vboot: add vb2api_use_short_dev_screen_delay() to 2api.h

Add vb2api_use_short_dev_screen_delay() to vboot2 API.

BRANCH=none
BUG=b:146399181, b:157871585
TEST=make runtests

Change-Id: Ice4852a7505e8dba73fa2026e8d433b8e487f556
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2235292
Reviewed-by: Joel Kitching <kitching@chromium.org>
5 files changed