drm/mgag200: Don't pass flags to drm_dev_register()

The flags argument is only relevant for UMS drivers. Pass 0.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702075642.27834-2-tzimmermann@suse.de

drivers/gpu/drm/mgag200/mgag200_drv.c

@@ -355,7 +355,7 @@ mgag200_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		return PTR_ERR(mdev);
 	dev = &mdev->base;
 
-	ret = drm_dev_register(dev, ent->driver_data);
+	ret = drm_dev_register(dev, 0);
 	if (ret)
 		return ret;