ahci: st: Switch from CONFIG_PM_SLEEP guards to pm_sleep_ptr()

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 kernel configuration guards.

Signed-off-by: Raphael Gallais-Pou <[e-mail]>
Reviewed-by: Niklas Cassel <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Niklas Cassel <[e-mail]>

drivers/ata/ahci_st.c

···
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int st_ahci_suspend(struct device *dev)
 {
 	struct ata_host *host = dev_get_drvdata(dev);
···
 
 	return ahci_platform_resume_host(dev);
 }
-#endif
 
-static SIMPLE_DEV_PM_OPS(st_ahci_pm_ops, st_ahci_suspend, st_ahci_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(st_ahci_pm_ops, st_ahci_suspend, st_ahci_resume);
 
 static const struct of_device_id st_ahci_match[] = {
 	{ .compatible = "st,ahci", },
···
 static struct platform_driver st_ahci_driver = {
 	.driver = {
 		.name = DRV_NAME,
-		.pm = &st_ahci_pm_ops,
+		.pm = pm_sleep_ptr(&st_ahci_pm_ops),
 		.of_match_table = st_ahci_match,
 	},
 	.probe = st_ahci_probe,