mlxsw: reg: Add local-port to Infiniband port mapping

In order to change a port type to Infiniband port we should change his
mapping from local-port to Infiniband. Adding the PLIB (Port Local to
InfiniBand) allows this mapping.

Signed-off-by: Elad Raz <eladr@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>