PM / devfreq: exynos: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions

This macro has the advantage over SET_SYSTEM_SLEEP_PM_OPS that we don't
have to care about when the functions are actually used.

Also make use of pm_sleep_ptr() to discard all PM_SLEEP related
stuff if CONFIG_PM_SLEEP isn't enabled.

Link: https://lore.kernel.org/lkml/[e-mail]/
Signed-off-by: Anand Moon <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>

drivers/devfreq/exynos-bus.c

···
 	devfreq_suspend_device(bus->devfreq);
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int exynos_bus_resume(struct device *dev)
 {
 	struct exynos_bus *bus = dev_get_drvdata(dev);
···
 
 	return 0;
 }
-#endif
 
-static const struct dev_pm_ops exynos_bus_pm = {
-	SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
-};
+static DEFINE_SIMPLE_DEV_PM_OPS(exynos_bus_pm,
+				exynos_bus_suspend, exynos_bus_resume);
 
 static const struct of_device_id exynos_bus_of_match[] = {
 	{ .compatible = "samsung,exynos-bus", },
···
 	.shutdown	= exynos_bus_shutdown,
 	.driver = {
 		.name	= "exynos-bus",
-		.pm	= &exynos_bus_pm,
+		.pm	= pm_sleep_ptr(&exynos_bus_pm),
 		.of_match_table = exynos_bus_of_match,
 	},
 };