HID: do not try to compile PM code with CONFIG_PM unset

Fixes this build breakage in case when CONFIG_PM is not set

drivers/hid/usbhid/hid-core.c: In function 'hid_suspend':
drivers/hid/usbhid/hid-core.c:1220: error: 'struct usb_device' has no member named 'auto_pm'
drivers/hid/usbhid/hid-core.c:1245: error: 'struct usb_device' has no member named 'auto_pm'
drivers/hid/usbhid/hid-core.c:1258: error: 'struct usb_device' has no member named 'auto_pm'

by throwing both the hid_suspend() and hid_resume() away completely
in such case, as they won't be used anyway.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/hid/usbhid/hid-core.c

@@ -1210,6 +1210,7 @@ static void hid_cease_io(struct usbhid_device *usbhid)
 	flush_scheduled_work();
 }
 
+#ifdef CONFIG_PM
 static int hid_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct hid_device *hid = usb_get_intfdata(intf);
@@ -1292,6 +1293,8 @@ static int hid_resume(struct usb_interface *intf)
 	return 0;
 }
 
+#endif /* CONFIG_PM */
+
 /* Treat USB reset pretty much the same as suspend/resume */
 static int hid_pre_reset(struct usb_interface *intf)
 {
@@ -1353,9 +1356,11 @@ static struct usb_driver hid_driver = {
 	.name =		"usbhid",
 	.probe =	hid_probe,
 	.disconnect =	hid_disconnect,
+#ifdef CONFIG_PM
 	.suspend =	hid_suspend,
 	.resume =	hid_resume,
 	.reset_resume =	hid_post_reset,
+#endif
 	.pre_reset =	hid_pre_reset,
 	.post_reset =	hid_post_reset,
 	.id_table =	hid_usb_ids,