rtc: efi: switch to devm_rtc_allocate_device

Switch to devm_rtc_allocate_device/devm_rtc_register_device, this allows
for further improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220309162301.61679-23-alexandre.belloni@bootlin.com

drivers/rtc/rtc-efi.c

@@ -261,15 +261,16 @@ static int __init efi_rtc_probe(struct platform_device *dev)
 	if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
 		return -ENODEV;
 
-	rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
-					THIS_MODULE);
+	rtc = devm_rtc_allocate_device(&dev->dev);
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
 
-	rtc->uie_unsupported = 1;
 	platform_set_drvdata(dev, rtc);
 
-	return 0;
+	rtc->ops = &efi_rtc_ops;
+	rtc->uie_unsupported = 1;
+
+	return devm_rtc_register_device(rtc);
 }
 
 static struct platform_driver efi_rtc_driver = {