add Berkeley specific copyright notice

add Berkeley specific copyright notice

SCCS-vsn: lib/libc/sys/fcntl.2 6.5
SCCS-vsn: lib/libc/sys/flock.2 6.5
SCCS-vsn: lib/libc/sys/fsync.2 6.5
SCCS-vsn: lib/libc/sys/getdtablesize.2 6.3
SCCS-vsn: lib/libc/sys/getgroups.2 6.5
SCCS-vsn: lib/libc/compat-43/gethostid.3 6.4
SCCS-vsn: lib/libc/gen/gethostname.3 6.5
SCCS-vsn: lib/libc/sys/getitimer.2 6.4
SCCS-vsn: lib/libc/gen/getpagesize.3 6.2
SCCS-vsn: lib/libc/sys/getpriority.2 6.7
SCCS-vsn: lib/libc/sys/getrlimit.2 6.5
SCCS-vsn: lib/libc/sys/gettimeofday.2 6.9
SCCS-vsn: lib/libc/sys/mkdir.2 6.5
SCCS-vsn: lib/libc/sys/readlink.2 6.5
SCCS-vsn: lib/libc/sys/reboot.2 6.2
SCCS-vsn: lib/libc/sys/rename.2 6.5
SCCS-vsn: lib/libc/sys/rmdir.2 6.4
SCCS-vsn: lib/libc/sys/setgroups.2 6.5
SCCS-vsn: lib/libc/compat-43/setreuid.2 6.2
SCCS-vsn: lib/libc/sys/shutdown.2 6.2
SCCS-vsn: lib/libc/compat-43/sigblock.2 6.4
SCCS-vsn: lib/libc/compat-43/sigpause.2 6.3
SCCS-vsn: lib/libc/sys/sigreturn.2 6.3
SCCS-vsn: lib/libc/compat-43/sigsetmask.2 6.4
SCCS-vsn: lib/libc/sys/sigstack.2 6.3
SCCS-vsn: lib/libc/compat-43/sigvec.2 6.4
SCCS-vsn: lib/libc/sys/swapon.2 6.5
SCCS-vsn: lib/libc/sys/symlink.2 6.4
SCCS-vsn: lib/libc/sys/truncate.2 6.7