QmlDesigner: Make NavigatorTreeModel::InternalIdRole public

Change-Id: I348b49a180138908b6a16be6e63d7b5adf38a5da
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

src/plugins/qmldesigner/components/navigator/navigatortreemodel.h

@@ -80,11 +80,12 @@ class NavigatorTreeModel : public QStandardItemModel
 {
     Q_OBJECT
 
+public:
     enum {
         InternalIdRole = Qt::UserRole
     };
 
-public:
+
     NavigatorTreeModel(QObject *parent = 0);
     ~NavigatorTreeModel();