mlxsw: spectrum_ethtool: Move mlxsw_sp_port_type_speed_ops structs

Move mlxsw_sp1_port_type_speed_ops and mlxsw_sp2_port_type_speed_ops
with the relevant code from spectrum.c to spectrum_ethtool.c.

Signed-off-by: Amit Cohen <amitc@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>