arm64: xilinx: Put ethernet phys to mdio node

arm64: xilinx: Put ethernet phys to mdio node

All zynqmp boards have been already described via mdio node that's why also
convert the rest of the boards. With using mdio node there is an option to
add reset property for the whole mdio bus which is reflected by
's/phy-reset-gpios/reset-gpios/g' for some boards.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/ff165281a70a38e2b76fee91e6255ce95ce8021b.1695378830.git.michal.simek@amd.com