net/mlx5e: Add missing 50G baseSR2 link mode

Add MLX5E_50GBASE_SR2 as ETHTOOL_LINK_MODE_50000baseSR2_Full_BIT.
Signed-off-by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Cc: Ben Hutchings <bwh@kernel.org>
Cc: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/en.h

@@ -616,6 +616,7 @@ enum mlx5e_link_mode {
 	MLX5E_10GBASE_ER	 = 14,
 	MLX5E_40GBASE_SR4	 = 15,
 	MLX5E_40GBASE_LR4	 = 16,
+	MLX5E_50GBASE_SR2	 = 18,
 	MLX5E_100GBASE_CR4	 = 20,
 	MLX5E_100GBASE_SR4	 = 21,
 	MLX5E_100GBASE_KR4	 = 22,