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/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index be3eb5e..bf7fea4 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -2310,6 +2310,7 @@
 	.get_tsf		= rt73usb_get_tsf,
 	.rfkill_poll		= rt2x00mac_rfkill_poll,
 	.flush			= rt2x00mac_flush,
+	.get_ringparam		= rt2x00mac_get_ringparam,
 };
 
 static const struct rt2x00lib_ops rt73usb_rt2x00_ops = {