Use the right data types to fix compiler warnings. Change-Id: Id23739421ba9e4a35599355fac9a17300ae4bda9 Signed-off-by: Mathias Krause <minipli@googlemail.com> Reviewed-on: http://review.coreboot.org/1236 Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Tested-by: build bot (Jenkins)