arm64: dts: socionext: uniphier-ld20: Add default PCI interrup controller address...

arm64: dts: socionext: uniphier-ld20: Add default PCI interrup controller address cells

Add missing address-cells 0 to the PCI interrupt node to silence W=1
warning:

  uniphier-ld20.dtsi:941.4-944.29: Warning (interrupt_map): /soc@0/pcie@66000000:interrupt-map:
    Missing property '#address-cells' in node /soc@0/pcie@66000000/legacy-interrupt-controller, using 0 as fallback

Value '0' is correct because:
1. GIC interrupt controller does not have children,
2. interrupt-map property (in PCI node) consists of five components and
   the fourth component "parent unit address", which size is defined by
   '#address-cells' of the node pointed to by the interrupt-parent
   component, is not used (=0)

Reviewed-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/20250822133318.312232-3-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>