[][OpenWrt Dev][Enable NMBM for mt7986 SNFI]

[Description]
Add and enable NMBM support for mt7986 SNFI

[Release-log]
N/A

Change-Id: I2ea42e0a5cc27d81556ea726cbd46a9880f1c85a
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4583323
3 files changed