arm64: dts: rockchip: Add regulators for PCIe for Radxa Rock Pi 4 board

Add 0.9V and 1.8V voltage regulators for Radxa Rock Pi 4 board PCIe.

Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Link: https://lore.kernel.org/r/20191120161302.5157-1-matwey@sai.msu.ru


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