media: rc: add keymap for Xbox 360 Universal Media remote

Captured using a raw IR receiver. Manual linked in the remote definition
itself.

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>