hid: force feedback driver for PantherLord USB/PS2 2in1 Adapter

Add a force feedback driver for PantherLord USB/PS2 2in1 Adapter,
0810:0001. The device identifies itself as "Twin USB Joystick".

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 523b834..18d0f2c 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -504,6 +504,7 @@
 int hid_ff_init(struct hid_device *hid);
 
 int hid_lgff_init(struct hid_device *hid);
+int hid_plff_init(struct hid_device *hid);
 int hid_tmff_init(struct hid_device *hid);
 int hid_zpff_init(struct hid_device *hid);
 #ifdef CONFIG_HID_PID