Fixed fallback to software rendering on Harmattan if GL context is lost.
Fixed fallback to software rendering on Harmattan if GL context is lost.

Set the shader type to QPainterVideoSurface::NoShaders to fallback
renderer if no gl context is svailable.

Task-number: PMO 283208
Reviewed-by: Michael Goddard

qtproject/qt-mobility,tmcguire/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,tmcguire/qt-mobility,tmcguire/qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,qtproject/qt-mobility,tmcguire/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,tmcguire/qt-mobility,qtproject/qt-mobility,qtproject/qt-mobility