mfd: hi6421-pmic: Use devm_mfd_add_devices() for mfd_device registration

Use devm_mfd_add_devices() for MFD devices registration and get
rid of .remove callback to remove MFD child-devices. This is done
by managed device framework.

CC: Guodong Xu <guodong.xu@linaro.org>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/hi6421-pmic-core.c

@@ -76,7 +76,7 @@ static int hi6421_pmic_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, pmic);
 
-	ret = mfd_add_devices(&pdev->dev, 0, hi6421_devs,
+	ret = devm_mfd_add_devices(&pdev->dev, 0, hi6421_devs,
 				   ARRAY_SIZE(hi6421_devs), NULL, 0, NULL);
 	if (ret) {
 		dev_err(&pdev->dev, "add mfd devices failed: %d\n", ret);
@@ -86,13 +86,6 @@ static int hi6421_pmic_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int hi6421_pmic_remove(struct platform_device *pdev)
-{
-	mfd_remove_devices(&pdev->dev);
-
-	return 0;
-}
-
 static const struct of_device_id of_hi6421_pmic_match_tbl[] = {
 	{ .compatible = "hisilicon,hi6421-pmic", },
 	{ },
@@ -105,7 +98,6 @@ static struct platform_driver hi6421_pmic_driver = {
 		.of_match_table = of_hi6421_pmic_match_tbl,
 	},
 	.probe	= hi6421_pmic_probe,
-	.remove	= hi6421_pmic_remove,
 };
 module_platform_driver(hi6421_pmic_driver);