Tell the compiler to use unsigned constants for left shift ops,
otherwise building with gcc >= 6.0 fails due to multiple warnings like:
warning: left shift of negative value [-Wshift-negative-value]
Signed-off-by: Panu Matilainen <pmatilai@redhat.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>