arm64: dts: rockchip: Remove unnecessary reset in rk3328.dtsi

Rockchip DWMAC glue driver uses the phy node (phy-handle)
reset specifier, and not a "mac-phy" reset specifier.

Remove it.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: David S. Miller <davem@davemloft.net>