Qt/GraphicsWindow: Disable unsupported options

Source/Core/DolphinQt2/Config/Graphics/HacksWidget.h

@@ -21,6 +21,8 @@ private:
   void LoadSettings() override;
   void SaveSettings() override;
 
+  void OnBackendChanged(const QString& backend_name);
+
   // EFB
   QCheckBox* m_skip_efb_cpu;
   QCheckBox* m_ignore_format_changes;