Some ports may have more than one `config.sub` that is in use (vendored
dependencies, etc.). Instead of fiddling about with space-delimited
strings, let's just make that setting into an array right away.
All of these patches did the same thing, which is already in upstream
config.sub.
With this change, we need only add `use_fresh_config_sub=true` to
the package.sh file.
Note that this is not done automatically in case the port has a modified
config.sub file.
We may need entries with spaces in makeopts, installopts, and
configopts, and at that point we should also convert depends and
auth_opts to avoid confusion.
