Remove FreeBSD packaging

The packaging used by official FreeBSD package builds is taken from
the FreeBSD Ports Collection's version control, which is currently
available at https://svnweb.freebsd.org/ports/head/net/openafs/ .

The version of the FreeBSD packaging in the openafs repository
will almost always be out-of-date and is not needed by FreeBSD
(although a small portion of it is currently used by the upstream
FreeBSD packaging), and the actual packaging used by FreeBSD is
easily available, so there is no purpose in maintaining FreeBSD
packaging in the OpenAFS source code repository.

Change-Id: I969cd6933ecd56d6940b8d48da67f50260101571
Reviewed-on: http://gerrit.openafs.org/11622
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>