iio:light:apds9300: 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/20220130193147.279148-19-jic23@kernel.org

drivers/iio/light/apds9300.c

@@ -466,7 +466,6 @@ static int apds9300_remove(struct i2c_client *client)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int apds9300_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
@@ -493,11 +492,8 @@ static int apds9300_resume(struct device *dev)
 	return ret;
 }
 
-static SIMPLE_DEV_PM_OPS(apds9300_pm_ops, apds9300_suspend, apds9300_resume);
-#define APDS9300_PM_OPS (&apds9300_pm_ops)
-#else
-#define APDS9300_PM_OPS NULL
-#endif
+static DEFINE_SIMPLE_DEV_PM_OPS(apds9300_pm_ops, apds9300_suspend,
+				apds9300_resume);
 
 static const struct i2c_device_id apds9300_id[] = {
 	{ APDS9300_DRV_NAME, 0 },
@@ -509,7 +505,7 @@ MODULE_DEVICE_TABLE(i2c, apds9300_id);
 static struct i2c_driver apds9300_driver = {
 	.driver = {
 		.name	= APDS9300_DRV_NAME,
-		.pm	= APDS9300_PM_OPS,
+		.pm	= pm_sleep_ptr(&apds9300_pm_ops),
 	},
 	.probe		= apds9300_probe,
 	.remove		= apds9300_remove,