arm64: dts: qcom: msm8996: add GCC's optional clock sources

Add missing GCC clock sources. This includes PCIe and USB PIPE and UFS
symbol clocks.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220620071936.1558906-4-dmitry.baryshkov@linaro.org