net/mlx4_en: Set number of rx/tx channels using ethtool

Add support to changing number of rx/tx channels using
ethtool ('ethtool -[lL]'). Where the number of tx channels specified in ethtool
is the number of rings per user priority - not total number of tx rings.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_main.c b/drivers/net/ethernet/mellanox/mlx4/en_main.c
index a52922e..3a2b8c6 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_main.c
@@ -250,7 +250,7 @@
 				rounddown_pow_of_two(max_t(int, MIN_RX_RINGS,
 							   min_t(int,
 								 dev->caps.num_comp_vectors,
-								 MAX_RX_RINGS)));
+								 DEF_RX_RINGS)));
 		} else {
 			mdev->profile.prof[i].rx_ring_num = rounddown_pow_of_two(
 				min_t(int, dev->caps.comp_pool/