ARM: select PCI_DOMAINS config from ARCH_MULTIPLATFORM

PCI_DOMAINS config should be selected for any SoCs
having more than a single PCIe controller. Without PCI_DOMAINS
config, only one PCIe controller gets registered.

Select PCI_DOMAINS in ARCH_MULTIPLATFORM if PCI is selected, since
it doesn't harm even if a platform has a single PCIe port.
Also remove PCI_DOMAINS being selected from other platform
specific configs.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>