ARM: dts: sun8i: a711: set regulator for each cluster of CPUs

The Allwinner A83T is a SoC with two clusters of 4 A7 which have a
different clock and regulator.

Set the CPU regulator.

Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>