rtc: ftrtc010: switch to devm_rtc_allocate_device

Switch to devm_rtc_allocate_device/rtc_register_device. This allow or
further improvement and simplifies ftrtc010_rtc_remove().
Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-ftrtc010.c

@@ -166,14 +166,18 @@ static int ftrtc010_rtc_probe(struct platform_device *pdev)
 	if (!rtc->rtc_base)
 		return -ENOMEM;
 
+	rtc->rtc_dev = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc->rtc_dev))
+		return PTR_ERR(rtc->rtc_dev);
+
+	rtc->rtc_dev->ops = &ftrtc010_rtc_ops;
+
 	ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
 			       IRQF_SHARED, pdev->name, dev);
 	if (unlikely(ret))
 		return ret;
 
-	rtc->rtc_dev = rtc_device_register(pdev->name, dev,
-					   &ftrtc010_rtc_ops, THIS_MODULE);
-	return PTR_ERR_OR_ZERO(rtc->rtc_dev);
+	return rtc_register_device(rtc->rtc_dev);
 }
 
 static int ftrtc010_rtc_remove(struct platform_device *pdev)
@@ -184,7 +188,6 @@ static int ftrtc010_rtc_remove(struct platform_device *pdev)
 		clk_disable_unprepare(rtc->extclk);
 	if (!IS_ERR(rtc->pclk))
 		clk_disable_unprepare(rtc->pclk);
-	rtc_device_unregister(rtc->rtc_dev);
 
 	return 0;
 }