arm64: rockchip_defconfig: fix softap error

arm64: rockchip_defconfig: fix softap error

fix error:
05-16 06:42:05.688   347   596 V NatController: runCmd(/system/bin/ip6tables -w -t raw -A natctrl_raw_PREROUTING -i wlan0 -m rpfilter --invert ! -s fe80::/64 -j DROP) res=1
05-16 06:42:05.726   347   596 E NatController: Error setting forward rules
05-16 06:42:05.791   602   622 E TetherInterfaceSM: Exception enabling Nat: java.lang.IllegalStateException: command '53 nat enable wlan0 eth0 1 192.168.43.0/24' failed with '400 53 Nat op
eration failed (No such device)'
05-16 06:42:05.794   347   841 D TetherController: Sending update msg to dnsmasq [update_ifaces|wlan0]
05-16 06:42:05.796   347   596 D TetherController: untetherInterface(wlan0)

Change-Id: Iae2ec50bef0915aecc1b2befb014a87731e61643
Signed-off-by: zzc <zzc@rock-chips.com>