dt-bindings: PCI: qcom-ep: Correct qcom,perst-regs

dt-bindings: PCI: qcom-ep: Correct qcom,perst-regs

qcom,perst-regs is an phandle array of one item with a phandle and its
arguments.

Link: https://lore.kernel.org/r/20221109113202.74406-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>