HID: lg4ff - Add range setting support and sysfs interface

Wheel range of certain Logitech wheels - namely Driving Force GT, Driving Force
Pro, G25 and G27 can be adjusted. Minimu is 40 degrees, maximum 900. DFGT, G25
and G27 all use a common command, DFP uses another one.  Range can be set from
userspace by writing to
"/sys/module/hid_logitech/drivers/hid:logitech/<dev>range". The driver use list
to store range of each connected wheel; it's not possible to use driver_data in
hid_device struct as it's already b hig-lg driver.

Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-lg.h b/drivers/hid/hid-lg.h
index b0100ba..3a32959 100644
--- a/drivers/hid/hid-lg.h
+++ b/drivers/hid/hid-lg.h
@@ -21,8 +21,10 @@
 
 #ifdef CONFIG_LOGIWII_FF
 int lg4ff_init(struct hid_device *hdev);
+int lg4ff_deinit(struct hid_device *hdev);
 #else
 static inline int lg4ff_init(struct hid_device *hdev) { return -1; }
+static inline int lg4ff_deinit(struct hid_device *hdev) { return -1; }
 #endif
 
 #endif