net: mediatek: add support for GMAC/USB3 PHY mux mode for MT7981

MT7981 has its GMAC2 PHY shared with USB3. To enable GMAC2, mux
register must be set to connect the SGMII phy to GMAC2.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
2 files changed