The TXQ path restructure requires ieee80211_tx_dequeue() to call TX
handlers and parts of the xmit_fast path. Move the function to later in
tx.c in preparation for this.
Signed-off-by: NToke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>