The relative pointer only has 2 axis, if we want to route the mouse
wheel events to that device, we need to add the axis definition, similar
to what is done for the absolute pointer.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Related: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1130