Bug#751565: libc: clock regression from wheezy on kfreebsd

[Petr Salinger <Petr.Salinger@seznam.cz>]

notfound 751565 2.18-7

The regression is due to

2013-12-17  Joseph Myers  <joseph@codesourcery.com>

* sysdeps/unix/bsd/bits/posix_opt.h: Remove file.
* sysdeps/unix/bsd/clock.c: Likewise.
* sysdeps/unix/bsd/times.c: Likewise.

I will resurrect the clock.c file into kfreebsd specific sysdeps,
and I will look at other deleted files.

Petr