iio:dac:m62332: 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.

Note that in this case the storage for saving state was protected
by CONFIG_PM guards. The storage is very small and unlikely to make
any real difference to the space allocated for state so just drop
those 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/20220130193147.279148-41-jic23@kernel.org

drivers/iio/dac/m62332.c

@@ -25,9 +25,7 @@ struct m62332_data {
 	struct regulator	*vcc;
 	struct mutex		mutex;
 	u8			raw[M62332_CHANNELS];
-#ifdef CONFIG_PM_SLEEP
 	u8			save[M62332_CHANNELS];
-#endif
 };
 
 static int m62332_set_value(struct iio_dev *indio_dev, u8 val, int channel)
@@ -124,7 +122,6 @@ static int m62332_write_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int m62332_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -156,11 +153,7 @@ static int m62332_resume(struct device *dev)
 	return m62332_set_value(indio_dev, data->save[1], 1);
 }
 
-static SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);
-#define M62332_PM_OPS (&m62332_pm_ops)
-#else
-#define M62332_PM_OPS NULL
-#endif
+static DEFINE_SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);
 
 static const struct iio_info m62332_info = {
 	.read_raw = m62332_read_raw,
@@ -246,7 +239,7 @@ MODULE_DEVICE_TABLE(i2c, m62332_id);
 static struct i2c_driver m62332_driver = {
 	.driver = {
 		.name	= "m62332",
-		.pm	= M62332_PM_OPS,
+		.pm	= pm_sleep_ptr(&m62332_pm_ops),
 	},
 	.probe		= m62332_probe,
 	.remove		= m62332_remove,