wl12xx: implement Tx watermarks per AC

Each AC is stopped when its queue is filled up to the high watermark,
and restarted when its queue it lower than the low watermark. This
ensures congested ACs are not able to starve other ACs.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h
index 000dfcd..94bfc0a 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -439,6 +439,7 @@
 	/* Frames scheduled for transmission, not handled yet */
 	struct sk_buff_head tx_queue[NUM_TX_QUEUES];
 	int tx_queue_count;
+	long stopped_queues_map;
 
 	/* Frames received, not handled yet by mac80211 */
 	struct sk_buff_head deferred_rx_queue;