libcamera: Mark overridden functions with override

Several overridden virtual functions are not marked with override. Fix
it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/pipeline/vimc.cpp

@@ -42,7 +42,7 @@ public:
 
 	int queueRequest(Camera *camera, Request *request) override;
 
-	bool match(DeviceEnumerator *enumerator);
+	bool match(DeviceEnumerator *enumerator) override;
 
 private:
 	class VimcCameraData : public CameraData