HID: wiimote: Register input device in wiimote hid driver

Register input device so the wiimote can report input events on
it. We do not use HIDINPUT because the wiimote does not provide any
descriptor table which might be used by HIDINPUT. So we avoid
having HIDINPUT parse the wiimote descriptor and create unrelated
or unknown event flags. Instead we register our own input device
that we have full control of.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>