PCI: hisi: Add HiSilicon SoC Hip05 PCIe driver

Add PCIe host support for HiSilicon SoC Hip05, related DT binding
documentation, and maintainer update.

[bhelgaas: changelog, 32-bit only config write warning text]
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Signed-off-by: liudongdong <liudongdong3@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rob Herring <robh@kernel.org> (DT binding)