[][MAC80211][hnat][Fix issue of multiple PPEs unbind for ETH in mt7981/7986]

[Description]
Fix issue of multiple PPEs unbind for ETH in mt7981/7986.

Without this patch, the traffic from eth1 to eth0 cannot be bind when
multiple PPEs are enabled.

[Release-log]
N/A


Change-Id: If71f1f7dc1bc220af9a3d2ad96e2bad93a3a2877
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8814903
4 files changed