qt: Add DnD support for cassette/cartridge media types

src/qt/qt_mediamenu.hpp

@@ -25,6 +25,7 @@ public:
     void cassetteUpdateMenu();
 
     void cartridgeSelectImage(int i);
+    void cartridgeMount(int i, const QString& filename);
     void cartridgeEject(int i);
     void cartridgeUpdateMenu(int i);