Enable flicking on touch based devices

The heuristic should probably be better but this will allow
ScrollView and TableView to at least support basic touch input.

Change-Id: I5904a0f2a29659e4cb0c3e7978ca0aa72d2415c4
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>