HID: multitouch: remove #ifdef CONFIG_PM

Through the usage of pm_ptr() the CONFIG_PM-dependent code will always be
compiled, protecting against bitrot.
The linker will then garbage-collect the unused function avoiding any overhead.

Signed-off-by: Thomas Weißschuh <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Benjamin Tissoires <[e-mail]>

drivers/hid/hid-multitouch.c

···
 	return 0;
 }
 
-#ifdef CONFIG_PM
 static int mt_suspend(struct hid_device *hdev, pm_message_t state)
 {
 	struct mt_device *td = hid_get_drvdata(hdev);
···
 
 	return 0;
 }
-#endif
 
 static void mt_remove(struct hid_device *hdev)
 {
···
 	.usage_table = mt_grabbed_usages,
 	.event = mt_event,
 	.report = mt_report,
-#ifdef CONFIG_PM
-	.suspend = mt_suspend,
-	.reset_resume = mt_reset_resume,
-	.resume = mt_resume,
-#endif
+	.suspend = pm_ptr(mt_suspend),
+	.reset_resume = pm_ptr(mt_reset_resume),
+	.resume = pm_ptr(mt_resume),
 };
 module_hid_driver(mt_driver);