[][kernel][mt7988][eth][Add support for the permanent MAC address of the ethtool]

[Description]
Add support for the permanent MAC address of the ethtool.

Usage: ethtool -P ethX

Without this patch, the ethtool is unable to retrieve the permanent MAC
address from the NAND/NOR Flash.

[Release-log]
N/A


Change-Id: I99507ca05c62318af43907545bbf535dfdb5e098
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/9034726
21 files changed