Add a method WAKS to devtree.asl which returns the wake-up source register to simplify retrieving the wake source e.g. in \_WAK. Change-Id: Ia258f8fc9ff79b18391c55464da73863889e2255 Signed-off-by: Christoph Grenz <christophg+cb@grenz-bonn.de> Reviewed-on: http://review.coreboot.org/297 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>