rt2x00: remove NOTICE

We use this macro only on 3 places - remove it and replace by other
appropriate macros for printing messages.

Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>