The Wii U Pro Controller is a new Nintendo remote device that looks very
similar to the XBox controller. It has nearly the same features and uses
the same protocol as the Wii Remote.

We add a new wiimote extension device so the Pro Controller is properly
detected and supported.

The device reports MP support, which is odd and I couldn't get it working,
yet. Hence, we disable MP registers for now. Further investigation is
needed to see what extra capabilities are provided.

There are some other unknown bits in the extension reports that I couldn't
figure out what they do. You can use hidraw to access these if you're
interested.

We might want to hook up the "charging" and "USB" bits to the battery
device so user-space can query whether it is currently charged via USB.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>