Like all supported formats (I think), LZO is optional. I don't see
any reason to bother with options for now, so I've just enabled it. Plus,
there's a bug in this release that makes compilation fail if LZO is
disabled due to a missing include. I've sent a fix[1] for that
upstream.
[1]: https://github.com/AgentD/squashfs-tools-ng/pull/41