wlcore: improved Tx scheduling algorithm

Prioritize EDCA by choosing the AC before anything else. Use the
fast/slow link bitmap in FW to improve the scheduling algorithm for
the multi-link scenario.

Set packet thresholds to determine if a given link is high or low
priority according to its speed. A slow link will be given high priority
if the amount of packets queued for it in the FW is lower than the
slow-threshold. Similarly, a fast link will be given high priority if
the number of its packets queued in FW is smaller than the high-threshold.

The improved algorithm:
1. Choose optimal AC according to FW utilization
2. Traversing the VIFs in a round-robin fashion, try to choose a high
   priority link. Links are traversed in a round-robin fashion inside a
   VIF.
3. If no high priority links are found, choose the first non-empty
   (low priority) link found in the round robin.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/ti/wl12xx/main.c

@@ -210,6 +210,8 @@ static struct wlcore_conf wl12xx_conf = {
 		.tmpl_short_retry_limit      = 10,
 		.tmpl_long_retry_limit       = 10,
 		.tx_watchdog_timeout         = 5000,
+		.slow_link_thold             = 3,
+		.fast_link_thold             = 10,
 	},
 	.conn = {
 		.wake_up_event               = CONF_WAKE_UP_EVENT_DTIM,