sky2: dynamic size transmit ring

Allocate and size transmit ring based on parameters. Saves excess
space and allows configuring larger rings for testing.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index feb3204..2c262f7 100644
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -2011,6 +2011,7 @@
 
 	struct tx_ring_info  *tx_ring;
 	struct sky2_tx_le    *tx_le;
+	u16		     tx_ring_size;
 	u16		     tx_cons;		/* next le to check */
 	u16		     tx_prod;		/* next le to use */
 	u16		     tx_next;		/* debug only */