iio:magn:mmc35240: 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. Also use SIMPLE_DEV_PM_OPS instead
of open-coding the equivalent.

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/20220130193147.279148-32-jic23@kernel.org

drivers/iio/magnetometer/mmc35240.c

@@ -521,7 +521,6 @@ static int mmc35240_probe(struct i2c_client *client,
 	return devm_iio_device_register(&client->dev, indio_dev);
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int mmc35240_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
@@ -548,11 +547,9 @@ static int mmc35240_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
-static const struct dev_pm_ops mmc35240_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(mmc35240_suspend, mmc35240_resume)
-};
+static DEFINE_SIMPLE_DEV_PM_OPS(mmc35240_pm_ops, mmc35240_suspend,
+				mmc35240_resume);
 
 static const struct of_device_id mmc35240_of_match[] = {
 	{ .compatible = "memsic,mmc35240", },
@@ -576,7 +573,7 @@ static struct i2c_driver mmc35240_driver = {
 	.driver = {
 		.name = MMC35240_DRV_NAME,
 		.of_match_table = mmc35240_of_match,
-		.pm = &mmc35240_pm_ops,
+		.pm = pm_sleep_ptr(&mmc35240_pm_ops),
 		.acpi_match_table = ACPI_PTR(mmc35240_acpi_match),
 	},
 	.probe		= mmc35240_probe,