net/mlx5: Propagate LAG effective max_tx_speed to vports

net/mlx5: Propagate LAG effective max_tx_speed to vports

Currently, vports report only their parent's uplink speed, which in LAG
setups does not reflect the true aggregated bandwidth. This makes it
hard for upper-layer software to optimize load balancing decisions
based on accurate bandwidth information.

Fix the issue by calculating the possible maximum speed of a LAG as
the sum of speeds of all active uplinks that are part of the LAG.
Propagate this effective max speed to vports associated with the LAG
whenever a relevant event occurs, such as physical port link state
changes or LAG creation/modification.

With this change, upper-layer components receive accurate bandwidth
information corresponding to the active members of the LAG and can
make better load balancing decisions.

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>