Fix animations in static builds

Make sure qRegisterGuiGetInterpolator is called even for static builds.

Task-number: QTBUG-37341
Change-Id: I65735a558d5bbfaa02fa4ec47d55ddf33ca1991a
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>