devkeys: add key.versions and install kernel keys

This makes it usable by the signer and its scripts.

BUG=None
TEST=signer can now sign recovery & factory images using these devkeys

Change-Id: I3f3443b93cfab2409ec591d5125bb03dc5e6bc4d
Reviewed-on: https://gerrit.chromium.org/gerrit/27781
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
3 files changed