[OpenAFS] AFS ntp docs

[Ken Dreyer]

>From the Unix Quickstart Guide[1]:

"Historically, AFS used to distribute its own version of the Network
Time Protocol Daemon. Whilst this is still provided for existing sites
..."

I'm guessing this is completely obsolete by now[2], and we can remove
the references in the OpenAFS docs?

- Ken

[1] http://docs.openafs.org/QuickStartUnix/ch02s18.html
[2] https://lists.openafs.org/pipermail/openafs-info/2002-August/005650.html