nvstorage: Add new flag VBNV_DEV_BOOT_FASTBOOT_FULL_CAP

Add a new flag to nvstorage for controlling fastboot capabilities
offered in firmware in dev-mode. By default, value of this flag would
be ignored in normal mode. Thus, when fastboot-based recovery is
entered from normal mode, only limited capability would be available
in firmware.

After switching to dev-mode, this flag can be set automatically by
user script after performing the wipe or it can be set manually using
crossystem. When fastboot-based recovery is entered from dev mode and
this flag is set, it will provide full fastboot capability in the
firmware.

BUG=chrome-os-partner:40196
BRANCH=None
TEST=Compiles successfully for smaug. make runalltests successful.

Change-Id: I761a9ab304dd90f0b73081acc9ce1f8d9052325f
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/271369
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Trybot-Ready: Furquan Shaikh <furquan@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
8 files changed