arm64: dts: rockchip: Add regulators for pcie on rk3399-rock960

As per Rock960 schematics add 0V9 and 1V8 voltage supplies to the
RK3399 PCIe block.

Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Link: https://lore.kernel.org/r/20191117140728.917-1-linux.amoon@gmail.com


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