net/mlx5: Add PPCNT physical layer statistical group infrastructure

Add the needed infrastructure for future use of PPCNT physical layer
statistical group.

Signed-off-by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index f21528a..5ad1d3c 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -1115,6 +1115,7 @@ enum {
 	MLX5_PER_PRIORITY_COUNTERS_GROUP      = 0x10,
 	MLX5_PER_TRAFFIC_CLASS_COUNTERS_GROUP = 0x11,
 	MLX5_PHYSICAL_LAYER_COUNTERS_GROUP    = 0x12,
+	MLX5_PHYSICAL_LAYER_STATISTICAL_GROUP = 0x16,
 	MLX5_INFINIBAND_PORT_COUNTERS_GROUP   = 0x20,
 };