mfd: intel_soc_pmic_chtwc: Switch from __maybe_unused 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 heavier for builds
than the use of __maybe_unused attributes.

Signed-off-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/mfd/intel_soc_pmic_chtwc.c

···
 	disable_irq(pmic->irq);
 }
 
-static int __maybe_unused cht_wc_suspend(struct device *dev)
+static int cht_wc_suspend(struct device *dev)
 {
 	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
 
···
 	return 0;
 }
 
-static int __maybe_unused cht_wc_resume(struct device *dev)
+static int cht_wc_resume(struct device *dev)
 {
 	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
 
···
 
 	return 0;
 }
-static SIMPLE_DEV_PM_OPS(cht_wc_pm_ops, cht_wc_suspend, cht_wc_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(cht_wc_pm_ops, cht_wc_suspend, cht_wc_resume);
 
 static const struct i2c_device_id cht_wc_i2c_id[] = {
 	{ }
···
 static struct i2c_driver cht_wc_driver = {
 	.driver	= {
 		.name	= "CHT Whiskey Cove PMIC",
-		.pm     = &cht_wc_pm_ops,
+		.pm     = pm_sleep_ptr(&cht_wc_pm_ops),
 		.acpi_match_table = cht_wc_acpi_ids,
 	},
 	.probe_new = cht_wc_probe,