On several A64 boards the Ethernet PHY is powered by the DC1SW regulator
on the AXP803 PMIC.

Add phy-handle property to these boards' emac node.
Signed-off-by: NIcenowy Zheng <icenowy@aosc.io>
Acked-by: NCorentin LABBE <clabbe.montjoie@gmail.com>
Tested-by: NCorentin LABBE <clabbe.montjoie@gmail.com>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>