rt2x00: Comment spellchecking

Fix a bunch of spelling errors in the rt2x00 drivers

Signed-off-by: Luis Correia <luis.f.correia@gmail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>