iio:light:rpr0521: Switch from CONFIG_PM guards to pm_ptr() etc

Letting the compiler remove these functions when the kernel is built
without CONFIG_PM support is simpler and less error prone than the
use of #ifdef based config guards.

Removing instances of this approach from IIO also stops them being
copied into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Mikko Koivunen <mikko.koivunen@fi.rohmeurope.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220130193147.279148-50-jic23@kernel.org

drivers/iio/light/rpr0521.c

@@ -1055,7 +1055,6 @@ static int rpr0521_remove(struct i2c_client *client)
 	return 0;
 }
 
-#ifdef CONFIG_PM
 static int rpr0521_runtime_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
@@ -1101,11 +1100,9 @@ static int rpr0521_runtime_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
 static const struct dev_pm_ops rpr0521_pm_ops = {
-	SET_RUNTIME_PM_OPS(rpr0521_runtime_suspend,
-			   rpr0521_runtime_resume, NULL)
+	RUNTIME_PM_OPS(rpr0521_runtime_suspend, rpr0521_runtime_resume, NULL)
 };
 
 static const struct acpi_device_id rpr0521_acpi_match[] = {
@@ -1124,7 +1121,7 @@ MODULE_DEVICE_TABLE(i2c, rpr0521_id);
 static struct i2c_driver rpr0521_driver = {
 	.driver = {
 		.name	= RPR0521_DRV_NAME,
-		.pm	= &rpr0521_pm_ops,
+		.pm	= pm_ptr(&rpr0521_pm_ops),
 		.acpi_match_table = ACPI_PTR(rpr0521_acpi_match),
 	},
 	.probe		= rpr0521_probe,