ARM: dts: BCM5301X: Add basic PCI controller properties

This fixes:
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@12000: 'device_type' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@12000: '#address-cells' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@12000: '#size-cells' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@13000: 'device_type' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@13000: '#address-cells' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@13000: '#size-cells' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@14000: 'device_type' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@14000: '#address-cells' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
arch/arm/boot/dts/bcm47081-buffalo-wzr-600dhp2.dtb: pcie@14000: '#size-cells' is a required property
        From schema: /lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml

What remains missing is "ranges" property. I currently don't know its
correct value for Northstar SoC.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20220721091509.27725-1-zajec5@gmail.com
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>