Input: pcfg8574_keypad - 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 #ifdef guards.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230102181842.718010-16-jic23@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/misc/pcf8574_keypad.c

@@ -167,7 +167,6 @@ static void pcf8574_kp_remove(struct i2c_client *client)
 	kfree(lp);
 }
 
-#ifdef CONFIG_PM
 static int pcf8574_kp_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -186,15 +185,8 @@ static int pcf8574_kp_suspend(struct device *dev)
 	return 0;
 }
 
-static const struct dev_pm_ops pcf8574_kp_pm_ops = {
-	.suspend	= pcf8574_kp_suspend,
-	.resume		= pcf8574_kp_resume,
-};
-
-#else
-# define pcf8574_kp_resume  NULL
-# define pcf8574_kp_suspend NULL
-#endif
+static DEFINE_SIMPLE_DEV_PM_OPS(pcf8574_kp_pm_ops,
+				pcf8574_kp_suspend, pcf8574_kp_resume);
 
 static const struct i2c_device_id pcf8574_kp_id[] = {
 	{ DRV_NAME, 0 },
@@ -205,9 +197,7 @@ MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);
 static struct i2c_driver pcf8574_kp_driver = {
 	.driver = {
 		.name  = DRV_NAME,
-#ifdef CONFIG_PM
-		.pm = &pcf8574_kp_pm_ops,
-#endif
+		.pm = pm_sleep_ptr(&pcf8574_kp_pm_ops),
 	},
 	.probe_new = pcf8574_kp_probe,
 	.remove   = pcf8574_kp_remove,