One of the most common uses of the rtl-sdr suite on OpenWrt is to stream
data to a remote analyzer. This commit creates a /etc/init.d/ and
/etc/config entry for rtl-tcp, so that it can automatically launch on
startup.

Signed-off-by: Mike Miller <github@mikeage.net>

Signed-off-by: Roger D <rogerdammit@gmail.com>

Signed-off-by: Roger D <rogerdammit@gmail.com>

Signed-off-by: Vasilis Tsiligiannis <acinonyx@openwrt.gr>