libc: move ftime to libc
It seems that there are still some applications that use ftime(3)
(for example, science/siconos, and sysutils/lcdproc). The issue
is that we don't build libcompat as a shared library anymore.
And even if we did, these applications are not linked to it.
The easiest solution is to move it to libc, until we deprecate
it for good.
This solution was proposed by kib@ in
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=257789.
Author of that bug refers to the issue with science/siconos,
and recently I had similar issue with sysutils/lcdproc.