Add a "debug_build" query to crossystem.

Querying "debug_build" allows the caller to determine whether the
image has requested debug, independent of the setting of the
dev_mode switch.

BUG=chromium:308678
BRANCH=none
TEST=use the new command option on both base and dev images

Change-Id: I369f26d75156f2e88d9f6f467efbf8f633e78bda
Reviewed-on: https://chromium-review.googlesource.com/174107
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Will Drewry <wad@chromium.org>
Commit-Queue: Richard Barnette <jrbarnette@chromium.org>
2 files changed