gpsd support

Before adding opencpn we need the gps support. So i used the latest stable version (3.9-r0) and added gps2udp. The recipe is very similar to the official gpsd recipe in the meta-oe layer, i only added gps2udp.

We run the gps suite in a wayland environment, thus gtk2-based programs aren't available (such as xgps and xgpsspeed). udev rules are also implemented so you only need to plug your gps device to start using it.