iio:adc:twl6030: Switch from CONFIG_PM_SLEEP guards 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 error prone than the
use of ifdef based config guards.

Removing instances of this approach from IIO also stops them being
copied into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220130193147.279148-15-jic23@kernel.org

drivers/iio/adc/twl6030-gpadc.c

@@ -944,7 +944,6 @@ static int twl6030_gpadc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int twl6030_gpadc_suspend(struct device *pdev)
 {
 	int ret;
@@ -968,9 +967,8 @@ static int twl6030_gpadc_resume(struct device *pdev)
 
 	return 0;
 };
-#endif
 
-static SIMPLE_DEV_PM_OPS(twl6030_gpadc_pm_ops, twl6030_gpadc_suspend,
+static DEFINE_SIMPLE_DEV_PM_OPS(twl6030_gpadc_pm_ops, twl6030_gpadc_suspend,
 				twl6030_gpadc_resume);
 
 static struct platform_driver twl6030_gpadc_driver = {
@@ -978,7 +976,7 @@ static struct platform_driver twl6030_gpadc_driver = {
 	.remove		= twl6030_gpadc_remove,
 	.driver		= {
 		.name	= DRIVER_NAME,
-		.pm	= &twl6030_gpadc_pm_ops,
+		.pm	= pm_sleep_ptr(&twl6030_gpadc_pm_ops),
 		.of_match_table = of_twl6030_match_tbl,
 	},
 };