gups: modified benchmark to use 2M pages

Signed-off-by: Simon Gerber <simon.gerber@inf.ethz.ch>

GUPS: make GUPS run within DUNE

Signed-off-by: Stefan Kaestle <stefan.kaestle@inf.ethz.ch>

adapting GUPS to run on linux

Signed-off-by: Reto Achermann <reto.achermann@inf.ethz.ch>