rt2x00: Update author rt2800lib

rt2800lib has been under development of the rt2x00 project,
so add it to the author string for the module information.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>