wl18xx: set the number of Tx descriptors

Initialize the number of Tx-descriptors for the 18xx family.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/ti/wl18xx/main.c b/drivers/net/wireless/ti/wl18xx/main.c
index b298e01..68f5e09 100644
--- a/drivers/net/wireless/ti/wl18xx/main.c
+++ b/drivers/net/wireless/ti/wl18xx/main.c
@@ -325,6 +325,7 @@
 	wl->ops = &wl18xx_ops;
 	wl->ptable = wl18xx_ptable;
 	wl->rtable = wl18xx_rtable;
+	wl->num_tx_desc = 32;
 
 	return wlcore_probe(wl, pdev);
 }