arch-dtb: cascading properties should ignore current node

strangely enough, in device trees the current node properties
are ignored when cascading (for #address-cells and reg).

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
pci: extract the x64-specific stuff

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
aarch64: pci: first implementation

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>