net/mlx5: E-Switch, Cache vport vhca id on first cap query

We need vhca_id to set up the vhca_id to vport mapping for every vport,
for that we query the firmware in mlx5_esw_vport_vhca_id_set, and it is
redundant since in esw_vport_setup, we already query hca caps which has
the vhca_id, cache it there and save 2 extra fw queries per vport.

Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Alexei Lazar <alazar@nvidia.com>
Reviewed-by: Feng Liu <feliu@nvidia.com>