[][update code for gmac2 path at sgmii]

[Description]
Change code for gmac2 at sgmii path
 -when gmac2 work at sgmii,we need power off sgmii2 path
  but old code will power off sgmii1 path

[Release-log]
N/A

Change-Id: Ifaba13e71e44d049fbec25cecf7d4ce8bc23e266
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5862260
1 file changed