The LCD frequency can be up to 18Hz, which makes the screen refresh much faster.
But the touch screen can't support this.
Also average the points on the touch screen because otherwise we have too much noise
This bundles all the board specific code in the mcu crate. There's much
to do though, so this is just a rough start and when it's all done we
should probably squash this.
Since the mcu crate dependencies require nightly and our CI builds with
stable, this removes the mcu backend from the default build and the ci.
