[][Kernel][hnat][464xlat support on netfilter hnat]

[Description]
Add new feature support 464xlat on netfilter hnat
In the test environment, the skb through the user space,
resulting in loss of headroom info.
So the process changes a lot.
In order to reduce the risk, I implemented separately
and insert it into pre-routing and post-routing.
We can use xlat_toggle to control it.

[Release-log]
N/A


Change-Id: Ib00e0c6f3674ee287cb5b318d30a73da279596b9
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7395696
diff --git a/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_hnat/hnat.c b/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_hnat/hnat.c
index 9c40ac8..7cda69f 100644
--- a/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_hnat/hnat.c
+++ b/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_hnat/hnat.c
@@ -862,6 +862,8 @@
 	if (err)
 		pr_info("hnat roaming work fail\n");
 
+	INIT_LIST_HEAD(&hnat_priv->xlat.map_list);
+
 	return 0;
 
 err_out: