RDMA/mlx5: Change default device for LAG slaves in RDMA TRANSPORT namespaces

RDMA/mlx5: Change default device for LAG slaves in RDMA TRANSPORT namespaces

In case of a LAG configuration change the root namespace core device for
all of the LAG slaves to be the core device of the master device for
RDMA_TRANSPORT namespaces, in order to ensure all tables are created
through the master device.
Once the LAG is disabled revert back to the native core device.

Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
Link: https://patch.msgid.link/20251029-support-other-eswitch-v1-4-98bb707b5d57@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>