When mouse events are delivered using XInput2 then the wheel event is
missing on submenus, because XInput2 delivers the wheel event only to
the root menu.

Task-number: QTBUG-50996
Change-Id: I757c0b5e3aea4606d2e45dfc8180c263e02167ca
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>