dt-bindings: PCI: qcom: Add SDX65 SoC

Add PCIe EP compatible string for SDX65 SoC.

Link: https://lore.kernel.org/r/1680243502-23744-2-git-send-email-quic_rohiagar@quicinc.com
Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>