spi: mt7621: Use devm_spi_register_controller()

Now that clk_disable_unprepare(clk) is handled with a managed resource,
we can use devm_spi_register_controller() and axe the .remove function.

The order between spi_unregister_controller() and clk_disable_unprepare()
is still the same.
(see commit 46b5c4fb ("spi: mt7621: Don't leak SPI master in probe
error path") to see why it matters)
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/b7698e198acc998d99e7e7c895a2910f14f89443.1661599671.git.christophe.jaillet@wanadoo.frSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-mt7621.c

@@ -373,20 +373,7 @@ static int mt7621_spi_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = spi_register_controller(master);
-
-	return ret;
-}
-
-static int mt7621_spi_remove(struct platform_device *pdev)
-{
-	struct spi_controller *master;
-
-	master = dev_get_drvdata(&pdev->dev);
-
-	spi_unregister_controller(master);
-
-	return 0;
+	return devm_spi_register_controller(&pdev->dev, master);
 }
 
 MODULE_ALIAS("platform:" DRIVER_NAME);
@@ -397,7 +384,6 @@ static struct platform_driver mt7621_spi_driver = {
 		.of_match_table = mt7621_spi_match,
 	},
 	.probe = mt7621_spi_probe,
-	.remove = mt7621_spi_remove,
 };
 
 module_platform_driver(mt7621_spi_driver);