Added support for magnetometer MAG3110 on INGA 1.6

I added a driver, sensor interface and example usage for the MAG3110 on the new INGA 1.6 sensor node.

The driver and sensor interface are currently very basic, but it can read out raw magnetic values so it is usable for testing the new nodes.

Later there should be a possibility to calibrate the sensor and use it together with the accelerometer to make a tilt compensated compass.