ath9k_hw: fix hardware queue allocation

commit ad8fdccf9c197a89e2d2fa78c453283dcc2c343f upstream.

The driver passes the desired hardware queue index for a WMM data queue
in qinfo->tqi_subtype. This was ignored in ath9k_hw_setuptxqueue, which
instead relied on the order in which the function is called.

Reported-by: Hubert Feurstein <h.feurstein@gmail.com>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>