mlxsw: spectrum: Add port type-speed operations

Add port type-speed operations in order to have different operations for
different ASICs. For now, both ASICs use the same pointer.

Signed-off-by: Shalom Toledo <shalomt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>