drm/fsl-dcu: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230507162616.1368908-20-u.kleine-koenig@pengutronix.de

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c

@@ -346,7 +346,7 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int fsl_dcu_drm_remove(struct platform_device *pdev)
+static void fsl_dcu_drm_remove(struct platform_device *pdev)
 {
 	struct fsl_dcu_drm_device *fsl_dev = platform_get_drvdata(pdev);
 
@@ -354,13 +354,11 @@ static int fsl_dcu_drm_remove(struct platform_device *pdev)
 	drm_dev_put(fsl_dev->drm);
 	clk_disable_unprepare(fsl_dev->clk);
 	clk_unregister(fsl_dev->pix_clk);
-
-	return 0;
 }
 
 static struct platform_driver fsl_dcu_drm_platform_driver = {
 	.probe		= fsl_dcu_drm_probe,
-	.remove		= fsl_dcu_drm_remove,
+	.remove_new	= fsl_dcu_drm_remove,
 	.driver		= {
 		.name	= "fsl-dcu",
 		.pm	= &fsl_dcu_drm_pm_ops,