mailbox: stm32-ipcc: Use device-managed registration API

Get rid of some boilerplate driver removal code by using the newly added
device-managed registration API.
Reviewed-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/stm32-ipcc.c

@@ -299,7 +299,7 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 	for (i = 0; i < ipcc->controller.num_chans; i++)
 		ipcc->controller.chans[i].con_priv = (void *)i;
 
-	ret = mbox_controller_register(&ipcc->controller);
+	ret = devm_mbox_controller_register(dev, &ipcc->controller);
 	if (ret)
 		goto err_irq_wkp;
 
@@ -329,8 +329,6 @@ static int stm32_ipcc_remove(struct platform_device *pdev)
 {
 	struct stm32_ipcc *ipcc = platform_get_drvdata(pdev);
 
-	mbox_controller_unregister(&ipcc->controller);
-
 	if (ipcc->wkp)
 		dev_pm_clear_wake_irq(&pdev->dev);