iio: magnetometer: ak8974: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros

Using these new macros allows the compiler to remove the unused dev_pm_ops
structure and related functions if !CONFIG_PM without the need to mark
the functions __maybe_unused.
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: NPaul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220621202719.13644-36-jic23@kernel.org

drivers/iio/magnetometer/ak8974.c

@@ -985,7 +985,7 @@ static int ak8974_remove(struct i2c_client *i2c)
 	return 0;
 }
 
-static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
+static int ak8974_runtime_suspend(struct device *dev)
 {
 	struct ak8974 *ak8974 =
 		iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
@@ -996,7 +996,7 @@ static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused ak8974_runtime_resume(struct device *dev)
+static int ak8974_runtime_resume(struct device *dev)
 {
 	struct ak8974 *ak8974 =
 		iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
@@ -1024,12 +1024,8 @@ static int __maybe_unused ak8974_runtime_resume(struct device *dev)
 	return ret;
 }
 
-static const struct dev_pm_ops ak8974_dev_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
-				pm_runtime_force_resume)
-	SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
-			   ak8974_runtime_resume, NULL)
-};
+static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend,
+				 ak8974_runtime_resume, NULL);
 
 static const struct i2c_device_id ak8974_id[] = {
 	{"ami305", 0 },
@@ -1050,7 +1046,7 @@ MODULE_DEVICE_TABLE(of, ak8974_of_match);
 static struct i2c_driver ak8974_driver = {
 	.driver	 = {
 		.name	= "ak8974",
-		.pm = &ak8974_dev_pm_ops,
+		.pm = pm_ptr(&ak8974_dev_pm_ops),
 		.of_match_table = ak8974_of_match,
 	},
 	.probe	  = ak8974_probe,