wlcore/wl12xx: add hw op for setting frame length in tx_hw_desc

Each chip family indicates the length of a frame to the HW differently.
This includes different padding, alignment and other fields in the HW Tx
descriptor.

Put all wl12xx specific code in a hw op.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/ti/wlcore/wlcore.h b/drivers/net/wireless/ti/wlcore/wlcore.h
index f0ce69d..fa636e2 100644
--- a/drivers/net/wireless/ti/wlcore/wlcore.h
+++ b/drivers/net/wireless/ti/wlcore/wlcore.h
@@ -41,6 +41,9 @@
 	void (*set_tx_desc_blocks)(struct wl1271 *wl,
 				   struct wl1271_tx_hw_descr *desc,
 				   u32 blks, u32 spare_blks);
+	void (*set_tx_desc_data_len)(struct wl1271 *wl,
+				     struct wl1271_tx_hw_descr *desc,
+				     struct sk_buff *skb);
 	s8 (*get_pg_ver)(struct wl1271 *wl);
 	void (*get_mac)(struct wl1271 *wl);
 };