Input: ad7877 - switch to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr()

SIMPLE_DEV_PM_OPS() is deprecated as it requires explicit protection
against unused function warnings.  The new combination of pm_sleep_ptr()
and DEFINE_SIMPLE_DEV_PM_OPS() allows the compiler to see the functions,
thus suppressing the warning, but still allowing the unused code to be
removed. Thus also drop the __maybe_unused markings.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230102181842.718010-31-jic23@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/ad7877.c

@@ -788,7 +788,7 @@ static int ad7877_probe(struct spi_device *spi)
 	return 0;
 }
 
-static int __maybe_unused ad7877_suspend(struct device *dev)
+static int ad7877_suspend(struct device *dev)
 {
 	struct ad7877 *ts = dev_get_drvdata(dev);
 
@@ -797,7 +797,7 @@ static int __maybe_unused ad7877_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused ad7877_resume(struct device *dev)
+static int ad7877_resume(struct device *dev)
 {
 	struct ad7877 *ts = dev_get_drvdata(dev);
 
@@ -806,12 +806,12 @@ static int __maybe_unused ad7877_resume(struct device *dev)
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
 
 static struct spi_driver ad7877_driver = {
 	.driver = {
 		.name	= "ad7877",
-		.pm	= &ad7877_pm,
+		.pm	= pm_sleep_ptr(&ad7877_pm),
 	},
 	.probe		= ad7877_probe,
 };