KitConfigWidgets: Use override

Use override on all virtual methods implemented by classes derived
from KitConfigWidget.

Change-Id: I050a9dbfd79b3ebe73af712b71d855a85f332928
Reviewed-by: Tim Jenssen <tim.jenssen@theqtcompany.com>

src/plugins/cmakeprojectmanager/cmakekitconfigwidget.h

@@ -51,7 +51,7 @@ class CMakeKitConfigWidget : public ProjectExplorer::KitConfigWidget
     Q_OBJECT
 public:
     CMakeKitConfigWidget(ProjectExplorer::Kit *kit, const ProjectExplorer::KitInformation *ki);
-    virtual ~CMakeKitConfigWidget();
+    ~CMakeKitConfigWidget() override;
 
     // KitConfigWidget interface
     QString displayName() const override;