Deprecating old OpenJDK versions from ports

Hi!

I've submitted a patch to deprecate the no longer maintained versions of
OpenJDK from the ports tree:

https://reviews.freebsd.org/D54176

This leaves only the LTS versions for now, but I think it's worth also
keeping any other still maintained version available. For the moment the
latest available version (25) just happens to be an LTS version as well
:)

Please let me know what you think!

If there's any objections from the community I'd love to hear about it.

Take care!
Harald