rt2x00: Use rt2x00 queue numbering

Use the rt2x00 queue enumeration as much as possible,
removing the usage of the mac80211 queue numbering
wherever it is possible.

This makes it easier for mac80211 to change it queue
identification scheme without having to deal with
big changes in the rt2x00 code.

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