rt2x00: Implement get_ringparam callback function

With the get_ringparam callback function we can export ring parameters
to ethtool through the mac80211 interface.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index dcdc50d..f1d8f55 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -1254,6 +1254,8 @@
 		      const struct ieee80211_tx_queue_params *params);
 void rt2x00mac_rfkill_poll(struct ieee80211_hw *hw);
 void rt2x00mac_flush(struct ieee80211_hw *hw, bool drop);
+void rt2x00mac_get_ringparam(struct ieee80211_hw *hw,
+			     u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max);
 
 /*
  * Driver allocation handlers.