[][Fix HNAT and port6 SGMII SSC setting of Panther with non-DSA MT7531 driver]

[Description]
Fix HNAT setting, and disable port6 SGMII SSC of the patch
d3d666538e8d ("Add non-DSA MT7531 driver support on Panther")

[Release-log]
N/A

Change-Id: I4ef3e7b3a408d1bbb46131077ba62c406c03741e
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5737611
2 files changed