IB/mlx5: Add support for 400G_8X lane speed

IB/mlx5: Add support for 400G_8X lane speed

[ Upstream commit 88c9483faf15ada14eca82714114656893063458 ]

Currently, when driver queries PTYS to report which link speed is being
used on its RoCE ports, it does not check the case of having 400Gbps
transmitted over 8 lanes. Thus it fails to report the said speed and
instead it defaults to report 10G over 4 lanes.

Add a check for the said speed when querying PTYS and report it back
correctly when needed.

Fixes: 08e8676f1607 ("IB/mlx5: Add support for 50Gbps per lane link modes")
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/ec9040548d119d22557d6a4b4070d6f421701fd4.1678973994.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>