mlxsw: spectrum: Remove unsupported eth_proto_lp_advertise field in PTYS

Remove eth_proto_lp_advertise field in PTYS register since it is not
supported by the firmware.

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>