arm64: dts: rockchip: Enable PCIe controller on rock3a

Add the nodes to enable the PCIe controller on the
Radxa ROCK3 Model A board. Run test with the MT7921
pcie wireless card.

Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>
Link: https://lore.kernel.org/r/20220726023516.6487-1-amadeus@jmu.edu.cn


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