pci: pci_mvebu: Add support for Kirkwood PCIe controllers

Kirkwood uses macros KW_DEFADR_PCI_MEM and KW_DEFADR_PCI_IO for base
address of PCIe mappings. Size of PCIe windows is not defined in any macro
yet, so export them in new KW_DEFADR_PCI_MEM_SIZE and KW_DEFADR_PCI_IO_SIZE
macros.

Kirkwood arch code already maps mbus windows for io and mem, so avoid
calling mvebu_mbus_add_window_by_id() function which would try to do
duplicate window mapping.

Kirkwood PCIe controllers already use "marvell,kirkwood-pcie" DT compatible
string, so mark pci_mvebu.c driver as compatible for it.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>