HID: add proper support for Elecom BM084 bluetooth mouse

This patch removes the annoying feature of Elecoms BM084 to constantly scroll to the right.
The device can be found at:
http://www.dealextreme.com/details.dx/sku.15402



Signed-off-by: Richard Nauber <Richard.Nauber@gmail.com>
[jkosina@suse.cz: fix build error]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>