serial/tmas: remove briken pl011 implementation and replace by dummy.
serial/tmas: remove briken pl011 implementation and replace by dummy.

Signed-off-by: Moritz Hoffmann <53ba0aa052d551db5cb133c62d34e71044d0deba@hpe.com>

kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish