Activate trackball scroller on nav layer

Author: dhl

boards/shields/charybdis/charybdis_right.overlay

@@ -74,7 +74,7 @@
         device = <&trackball>;
 
         scroller {
-            layers = <3>;
+            layers = <1>;
             input-processors = <
                 &zip_xy_transform INPUT_TRANSFORM_Y_INVERT
                 &zip_xy_to_scroll_mapper