Since the change to use compose render-to-texture widgets through QRhi,
the RasterGLSurface is not existing anymore and it was used in QNX QPA
to check the support for using backingstore with non-raster windows.
With the use of QRhiBackingstore the QNX QPA now supports
render-to-texture widgets for non-raster surface windows.
Fixes: QTBUG-114938
Task-number: QTBUG-114938
Pick-to: 6.5 6.6 6.7
Change-Id: I01d4a34efe4902a527051776b0460ccf22e5d232
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Marianne Yrjänä <marianne.yrjana@qt.io>
c9ddc4b8e1