remove unnecessary GTK declarations from defs.h, move things only used once to the place that needs them

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69020 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/dvrenderer.h

@@ -48,7 +48,7 @@ public:
     //
     // it validates the new value and notifies the model about the change by
     // calling GtkOnCellChanged() if it was accepted
-    virtual void GtkOnTextEdited(const gchar *itempath, const wxString& value);
+    virtual void GtkOnTextEdited(const char *itempath, const wxString& value);
 
     GtkCellRenderer* GetGtkHandle() { return m_renderer; }
     void GtkInitHandlers();