libcamera: Replace toString with operator<<() for geometry classes

Now that geometry classes implement the stream formatting operator<<(),
use it instead of the toString() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/pipeline/vimc/vimc.cpp

@@ -164,7 +164,7 @@ CameraConfiguration::Status VimcCameraConfiguration::validate()
 
 	if (cfg.size != size) {
 		LOG(VIMC, Debug)
-			<< "Adjusting size to " << cfg.size.toString();
+			<< "Adjusting size to " << cfg.size;
 		status = Adjusted;
 	}