wl12xx: use 2 spare TX blocks for GEM cipher

Add tx_spare_blocks member to the wl1271 struct
for more generic configuration of the amount
of spare TX blocks that should be used.
The default value is 1.
In case GEM cipher is used by the STA, we need
2 spare TX blocks instead of just 1.

Signed-off-by: Guy Eilam <guy@wizery.com>
Acked-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 61a7c21..fb2753c 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -425,6 +425,9 @@
 	u32 tx_allocated_blocks;
 	u32 tx_results_count;
 
+	/* amount of spare TX blocks to use */
+	u32 tx_spare_blocks;
+
 	/* Accounting for allocated / available Tx packets in HW */
 	u32 tx_pkts_freed[NUM_TX_QUEUES];
 	u32 tx_allocated_pkts[NUM_TX_QUEUES];