[][kernel][mt7981][eth][Fix FC mis-match issue in externel phy]

[Description]
Fix FC mis-match issue in externel phy, the issue will cause a decrease
in T-put.

[Release-log]
N/A


Change-Id: Ib47fbee55b2cf78df79e41a3207091ba172d29f5
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7248826
1 file changed