arm64: dts: qcom: stop using snps,dw-pcie falback

Qualcomm PCIe devices are not really compatible with the snps,dw-pcie.
Unlike the generic IP core, they have special requirements regarding
enabling clocks, toggling resets, using the PHY, etc.

This is not to mention that platform snps-dw-pcie driver expects to find
two IRQs declared, while Qualcomm platforms use just one.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220506152107.1527552-6-dmitry.baryshkov@linaro.org