[][kernel][common][hnat][Add NETSYSv3 HNAT new feature support]

[Description]
Add NETSYSv3 HNAT new feature support.

If without this patch, driver can't work on the NETSYSv3 HNAT.

Patchset2: Update /LINUX/include/net/ra_nat.h.
Patchset3: Add Signed-off.
Patchset4: Remove space before tabs for skb_hnat_ppe2.

[Release-log]
N/A

Change-Id: Id5cacc431ff1867a8b69944a456de5916d2a0ab2
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6576784
Build: srv_hbgsm110
6 files changed