QtMultimediaKit should not use opengl in Symbian even if Qt is configured with opengl es2

Platform builds for Symbian^3 are built with -opengl es2 configuration. All libraries linking against QtMultimediaKit fails to compile on WINSCW because emulator lacks libglesv2.lib. For HW the build succeeds but won't work as expected. According to Jason Barron Symbian HW does not support render-to-texture and pixel access to video frame is not possible.

So the fix for now is to not use OpenGL in Symbian for QtMultimediaKit even if it is configured for Qt. Something in the lines of attached patch.

Originating issue QT-4308.