Add a script to remove /boot and its contents from an image.

This is a helper script intended for the signing servers to use to strip
out the /boot directory from images just before signing.

BUG=chromium:210352
TEST=Manually used to strip and image and validated the results.
BRANCH=None

Change-Id: I814522284143d8f90651e13000d428718aeca1e4
Reviewed-on: https://gerrit.chromium.org/gerrit/60828
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>
Tested-by: Don Garrett <dgarrett@chromium.org>
2 files changed