iio:proximity:rfd77492: Switch from CONFIG_PM_SLEEP guards to pm_sleep_ptr() etc

Letting the compiler remove these functions when the kernel is built
without CONFIG_PM_SLEEP 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>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220130193147.279148-35-jic23@kernel.org

drivers/iio/proximity/rfd77402.c

@@ -295,7 +295,6 @@ static int rfd77402_probe(struct i2c_client *client,
 	return devm_iio_device_register(&client->dev, indio_dev);
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int rfd77402_suspend(struct device *dev)
 {
 	return rfd77402_powerdown(to_i2c_client(dev));
@@ -305,9 +304,9 @@ static int rfd77402_resume(struct device *dev)
 {
 	return rfd77402_init(to_i2c_client(dev));
 }
-#endif
 
-static SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend, rfd77402_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend,
+				rfd77402_resume);
 
 static const struct i2c_device_id rfd77402_id[] = {
 	{ "rfd77402", 0 },
@@ -318,7 +317,7 @@ MODULE_DEVICE_TABLE(i2c, rfd77402_id);
 static struct i2c_driver rfd77402_driver = {
 	.driver = {
 		.name   = RFD77402_DRV_NAME,
-		.pm     = &rfd77402_pm_ops,
+		.pm     = pm_sleep_ptr(&rfd77402_pm_ops),
 	},
 	.probe  = rfd77402_probe,
 	.id_table = rfd77402_id,