On platforms with memory-mapped I/O ports, such as ia64 and ARM64, we have
to map the memory region and coordinate it with the arch's I/O port
accessors.

For ia64, we do this in arch code because it supports both dense (1 byte
per I/O port) and sparse (1024 bytes per I/O port) memory mapping.  For
arm64, we only support dense mappings, which we can do in the generic code
with pci_register_io_range() and pci_remap_iospace().

Add acpi_pci_root_remap_iospace() to remap dense memory-mapped I/O port
space when adding a bridge, and call pci_unmap_iospace() to release the
space when removing the bridge.

[bhelgaas: changelog, move #ifdef inside acpi_pci_root_remap_iospace()]
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
[Tomasz: merged in Sinan's patch to unmap IO resources properly, updated changelog]
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>