arm64: dts: qcom: sc8280xp: add missing PCIe minimum OPP

Add the missing PCIe CX performance level votes to avoid relying on
other drivers (e.g. USB or UFS) to maintain the nominal performance
level required for Gen3 speeds.

Fixes: 813e8315 ("arm64: dts: qcom: sc8280xp/sa8540p: add PCIe2-4 nodes")
Cc: stable@vger.kernel.org      # 6.2
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240306095651.4551-5-johan+linaro@kernel.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>