uplcom(4) update from FreeBSD

[Johannes Hofmann <Johannes.Hofmann@xxxxxx>]

At http://www.ecademix.com/JohannesHofmann/uplcom.diff.gz
I have a patch to update uplcom(4) to the newest version from
FreeBSD. This version supports the 2303X chiptype found in new
USB to serial dongles.
I only have one of these new type dongles, so I can't test for 
any regressions.

  Johannes