Commit 51bc085d ("PCI: Improve host drivers compile test coverage")
added configuration options to allow PCI host controller drivers to be
compile tested on all architectures.

Some host controller drivers (eg PCIE_ALTERA) config entries select the
PCI_DOMAINS config option to enable PCI domains management in the kernel.
Now that host controller drivers can be compiled on all architectures, this
triggers build regressions on arches that do not implement the PCI_DOMAINS
required API (ie pci_domain_nr()):

  drivers/ata/pata_ali.c: In function 'ali_init_chipset':
  drivers/ata/pata_ali.c:469:38: error: implicit declaration of function 'pci_domain_nr'; did you mean 'pci_iomap_wc'?

Furthemore, some software configurations (ie Jailhouse) require a
PCI_DOMAINS enabled kernel to configure multiple host controllers without
having an explicit dependency on the ARM platform on which they run.

Make PCI_DOMAINS a visible configuration option on ARM so that software
configurations that need it can manually select it and move the PCI_DOMAINS
selection from PCI controllers configuration file to ARM sub-arch config
entries that currently require it, fixing the issue.

Fixes: 51bc085d ("PCI: Improve host drivers compile test coverage")
Link: https://lkml.kernel.org/r/20180612170229.GA10141@roeck-us.netReported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Guenter Roeck <linux@roeck-us.net>