net/mlx5: Add max_tx_speed and its CAP bit to IFC

net/mlx5: Add max_tx_speed and its CAP bit to IFC

Introduce the max_tx_speed field to the query and modify_vport_state
structures.

Add the esw_vport_state_max_tx_speed capability bit, indicating
the firmware support modifying the max_tx_speed field via the
MODIFY_VPORT_STATE command.

Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Reviewed-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>