rtc: at91sam9: 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>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230304133028.2135435-7-u.kleine-koenig@pengutronix.deSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-at91sam9.c

@@ -442,7 +442,7 @@ static int at91_rtc_probe(struct platform_device *pdev)
 /*
  * Disable and remove the RTC driver
  */
-static int at91_rtc_remove(struct platform_device *pdev)
+static void at91_rtc_remove(struct platform_device *pdev)
 {
 	struct sam9_rtc	*rtc = platform_get_drvdata(pdev);
 	u32		mr = rtt_readl(rtc, MR);
@@ -451,8 +451,6 @@ static int at91_rtc_remove(struct platform_device *pdev)
 	rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
 
 	clk_disable_unprepare(rtc->sclk);
-
-	return 0;
 }
 
 static void at91_rtc_shutdown(struct platform_device *pdev)
@@ -531,7 +529,7 @@ MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
 
 static struct platform_driver at91_rtc_driver = {
 	.probe		= at91_rtc_probe,
-	.remove		= at91_rtc_remove,
+	.remove_new	= at91_rtc_remove,
 	.shutdown	= at91_rtc_shutdown,
 	.driver		= {
 		.name	= "rtc-at91sam9",