accessory: script to generically generate accessory keys

All accessories leverage the key format of Hammer therefore this
script calls Hammer's one to generate a key pair and renames them.
The key name isn't referenced by the signer anymore, so we will
name them all "hammerlike".

BUG=chromium:859269
TEST=Run this script in the chroot.
BRANCH=None

Change-Id: Iba35b03e59216e96a99f8aa471b660f3805c1f23
Reviewed-on: https://chromium-review.googlesource.com/1205636
Commit-Ready: Nick Sanders <nsanders@chromium.org>
Tested-by: Nick Sanders <nsanders@chromium.org>
Reviewed-by: Marco Chen <marcochen@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
6 files changed