dt-bindings: PCI: qcom: Add QCS404 to the binding

The Qualcomm QCS404 platform contains a PCIe controller, add this to the
Qualcomm PCI binding document. The controller is the same version as the
one used in IPQ4019, but the PHY part is described separately, hence the
difference in clocks and resets.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>