rt2x00: Fix WMM Queue naming

The Queue names were incorrectly copied from the legacy drivers,
as a result the queue names were inversed to what was expected.

This renames the queues using this mapping:
	QID_AC_BK -> QID_AC_VO (priority 0)
	QID_AC_BE -> QID_AC_VI (priority 1)
	QID_AC_VI -> QID_AC_BE (priority 2)
	QID_AC_VO -> QID_AC_BK (priority 3)

Note that this was a naming problem only, which didn't affect
the assignment of frames to their respective queues.

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