PolarChartAxis: call base class from updateGeometry overrides

While PolarChartAxis doesn't override updateGeometry, it is prudent
to not skip base classes as they might do so in the future.

Axivion warns about skipped base classes, and while it doesn't about
those specific cases, fix them anyway.

Task-number: QTBUG-146050
Pick-to: 6.12
Change-Id: Ia007af907ce8d531643865ec8a5ef7941301253f
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>