dt-bindings: PCI: qcom: Adjust iommu-map for different SoC

The PCIe controller on SDX55 has five entries in its iommu-map, MSM8998
has one and SDM845 has sixteen, so allow wider number of items to fix
dtbs_check warnings like:

  qcom-sdx55-mtp.dtb: pcie@1c00000: iommu-map: [[0, 21, 512, 1], [256, 21, 513, 1],
    [512, 21, 514, 1], [768, 21, 515, 1], [1024, 21, 516, 1]] is too long

Link: https://lore.kernel.org/linux-pci/20231208105155.36097-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>