[][add code deny traffic into FE when network restart]

[Description]
Add code to deny traffic entering FE
-- network restart may cause eth interface down/up
-- traffic into FE when networ restart may cause FE work abnormal
   -- disable cpu tx path
   -- set GMAC RX drop
   -- set phy or sgmii power down

[Release-log]

Change-Id: I4bf8a75a438375c28ae770602be1af15932f5109
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5597272
1 file changed