[][openwrt][mt7988][integration][Add basic Filogic 880 SoC support]

[Description]
Add basic filogic 880 SoC support to openwrt 21.02

[Release-log]

Change-Id: I57791df2e9f9f4729cb2d32f734090de52c370f2
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6592143
Build: srv_hbgsm110
58 files changed