arm64: dts: rockchip: fix cpu-supply for rk3328-evb

The property cpu-supply should be added to each cpu separately,
so fix that for rk3328-evb.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20200813181711.15906-1-jbx6244@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>