arm64: dts: allwinner: a64: olinuxino: Add bank supply regulators

Allwinner A64 SoC has separate supplies for PC, PD, PE, PG and PL. This
patch adds regulators for them to the pinctrl node.

Exception is PL which is used by the RSB bus. To avoid circular
dependencies, VCC-PL is omitted.

On boards with eMMC, VCC-PC is supplied by ELDO1, instead of DCDC1.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
[Maxime: Changed the r_pio comment a bit]
Signed-off-by: Maxime Ripard <maxime@cerno.tech>