PCI: qcom: Add support for IPQ8074 PCIe controller

Add support for the IPQ8074 PCIe controller.  IPQ8074 supports Gen 1/2, one
lane, two PCIe root complex with support for MSI and legacy interrupts, and
it conforms to PCI Express Base 2.1 specification.

The core init is the similar to the existing SoC, however the clocks and
reset lines differ.

Signed-off-by: smuthayy <smuthayy@codeaurora.org>
Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
[bhelgaas: fix capitalization and "dev" usage to match existing style]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>