HID: wiimote: convert LEDS to modules

Each of the 4 LEDs may be supported individually by devices. Therefore,
we need one module for each device. To avoid code-duplication, we simply
pass the LED ID as "arg" argument to the module loading code.

This just moves the code over to wiimote-module. The semantics stay the
same as before.

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