Add fedora-release-iot edition pieces
    
    This adds the fedora-release-iot package for the Fedora IoT edition.
    Note we don't add the option in the convert-to-edition script because
    as IoT is purely rpm-ostree based we can't covert to IoT edition in
    the traditional manner. We don't yet tweak presets but this is something
    we intend to do moving forward.
    
    Signed-off-by: Peter Robinson <pbrobinson@fedoraproject.org>