[sdk-3.4.14b] RTL8197开启Cone Nat support功能，支持设置NatType设置操作

[NATType]路由器四种NAT（NAT1 NAT2 NAT3 NAT4）类型说明_wgl307293845的博客-CSDN博客_nat类型

make linux_menuconfig
    -> Networking support (NET [=y])
        -> Networking options
            -> Network packet filtering framework (Netfilter) (NETFILTER [=y])
                -> IP: Netfilter Configuration
                -> IP tables support (required for filtering/masq/NAT) (IP_NF_IPTABLES [=y])
                -> Full NAT (NF_NAT [=y])
                    -> MASQUERADE target support (IP_NF_TARGET_MASQUERADE [=y])
                    -> IP_NF_TARGET_ConENAT [=y]