iio: adc: ti-am335x: Switch to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr()

Using these newer macros allows the compiler to remove the unused
structure and functions when !CONFIG_PM_SLEEP + removes the need to
mark pm functions __maybe_unused.

Signed-off-by: Jonathan Cameron <[e-mail]>
Cc: Miquel Raynal <[e-mail]>
Reviewed-by: Miquel Raynal <[e-mail]>
Reviewed-by: Paul Cercueil <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/iio/adc/ti_am335x_adc.c

···
 	return 0;
 }
 
-static int __maybe_unused tiadc_suspend(struct device *dev)
+static int tiadc_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
···
 	return 0;
 }
 
-static int __maybe_unused tiadc_resume(struct device *dev)
+static int tiadc_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
···
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(tiadc_pm_ops, tiadc_suspend, tiadc_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(tiadc_pm_ops, tiadc_suspend, tiadc_resume);
 
 static const struct of_device_id ti_adc_dt_ids[] = {
 	{ .compatible = "ti,am3359-adc", },
···
 static struct platform_driver tiadc_driver = {
 	.driver = {
 		.name   = "TI-am335x-adc",
-		.pm	= &tiadc_pm_ops,
+		.pm	= pm_sleep_ptr(&tiadc_pm_ops),
 		.of_match_table = ti_adc_dt_ids,
 	},
 	.probe	= tiadc_probe,