Fix build of compositors by always including QOpenGLContext.
Fix build of compositors by always including QOpenGLContext.

QOpenGLContext is always required even when QT_COMPOSITOR_WAYLAND_GL is
not defined.  Moving the include outside the ifdef makes compositors
build without problems.

Change-Id: I4b8903b06a5f58ad8fd2953dbde1476877683cb4
Reviewed-by: Laszlo Agocs <2e231a4a054e4f6029c4a14f9b35ccf5b686a0a1@nokia.com>

Tofee/qtwayland,Tofee/qtwayland,Tofee/qtwayland,locusf/qtwayland-1,ntanibata/qtwayland,ntanibata/qtwayland,locusf/qtwayland-1,locusf/qtwayland-1,locusf/qtwayland-1,ntanibata/qtwayland