dts: qemu: a53: kvm: add DTS support for PCIe controller

Add DTS information for qemu-virt-a53 and qemu-kvm-arm64 for PCIe
controller support. Three new bindings are required for the PCIe
controller in ECAM mode.

The DTS information was extracted from QEMU (dumpdtb) with a PCIe device
attached to the virtual machine (ivshmem)

Signed-off-by: Rodrigo Cataldo <rodrigo.cataldo@huawei.com>
Co-authored-by: Henri Xavier <datacomos@huawei.com>