iio:accel:dmard06: 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 <[e-mail]>
Reviewed-by: Paul Cercueil <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/iio/accel/dmard06.c

···
 	return devm_iio_device_register(&client->dev, indio_dev);
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int dmard06_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
···
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(dmard06_pm_ops, dmard06_suspend, dmard06_resume);
-#define DMARD06_PM_OPS (&dmard06_pm_ops)
-#else
-#define DMARD06_PM_OPS NULL
-#endif
+static DEFINE_SIMPLE_DEV_PM_OPS(dmard06_pm_ops, dmard06_suspend,
+				dmard06_resume);
 
 static const struct i2c_device_id dmard06_id[] = {
 	{ "dmard05", 0 },
···
 	.driver = {
 		.name = DMARD06_DRV_NAME,
 		.of_match_table = dmard06_of_match,
-		.pm = DMARD06_PM_OPS,
+		.pm = pm_sleep_ptr(&dmard06_pm_ops),
 	},
 };
 module_i2c_driver(dmard06_driver);