Add: Option to (dis-)allow accelerated video drivers. (#8819)

The video drivers using the OpenGL backend are currently our only
accelerated drivers. The options defaults to off for macOS builds and
to on everywhere else.

Co-authored-by: Michael Lutz <michi@icosahedron.de>

src/video/win32_v.h

@@ -175,6 +175,9 @@ class FVideoDriver_Win32OpenGL : public DriverFactoryBase {
 public:
 	FVideoDriver_Win32OpenGL() : DriverFactoryBase(Driver::DT_VIDEO, 10, "win32-opengl", "Win32 OpenGL Video Driver") {}
 	/* virtual */ Driver *CreateInstance() const override { return new VideoDriver_Win32OpenGL(); }
+
+protected:
+	bool UsesHardwareAcceleration() const override { return true; }
 };
 
 #endif /* WITH_OPENGL */