vboot: implement DISPLAY_INIT context and SD flag

As part of go/vboot2-cleanup-oprom, introduce new context
flag DISPLAY_INIT.  The equivalent shared data flag
DISPLAY_AVAILABLE is also introduced for downstream vboot
to read.

The context flag serves the dual purpose of:

(1) the vboot caller (coreboot) telling vboot that "display
    will be initialized regardless", for cases when a
    mainboard/SoC cannot disable its display initialization
    code (see coreboot Kconfig VBOOT_MUST_REQUEST_DISPLAY,
    previously VBOOT_OPROM_MATTERS).

(2) vboot telling the vboot caller (coreboot) that "display
    initialization should occur" for cases when vboot needs
    display enabled on this boot.

BUG=b:124141368, chromium:948529
TEST=make clean && make runtests
BRANCH=none

Change-Id: If18bedf99c0f6e366c12d043377edb7bcdb35fdf
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1564232
Commit-Ready: Joel Kitching <kitching@chromium.org>
Tested-by: Joel Kitching <kitching@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

0 files changed, 0 insertions, 0 deletions