Add magnetics board option

[xcancerberox]

In the future we want to use the magnetics in a separated board for quick exchange.

Further discussion needs to be made on this matter.

[xcancerberox]

We decided to use an existing connector that can be solder in the same place as the magnetics.

This is an option:

https://www.samtec.com/products/mle-112-01-g-dv-a

Then we can test the idea an in the future remove the circuit from the board.