Add systemd unit file for xinetd.
(From OE-Core rev: aa0a1cbc92a4d586377cb9e9827ee8b90749c364)
Signed-off-by: Chong Lu <Chong.Lu@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>