arm64: dts: allwinner: pinebook: Add GPIO port regulators

Allwinner A64 SoC has separate supplies for PC, PD, PE, PG and PL.

VCC-PC and VCC-PG are supplied by ELDO1 at 1.8v.
VCC-PD is supplied by DCDC1 (VCC-IO) at 3.3v.
VCC-PE is supplied by ALDO1, and is unused.

VCC-PL creates a circular dependency, so it is omitted for now.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>