Fix the y inversion of QWaylandSurfaceItem

Change-Id: Id42223b46658aa4cdcb0319ec5b6b2df9d8ca733
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Fix fetching of the y-inverted value fomr the wayland-egl integration

The default return value of isYInverted() is true, but we want to return
false by that point, unless the ifdeffed part was thrown away.

Change-Id: Ia875c1e3083c7c378cc7dd1f4b634f6fa7500f5b
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>