PCI: Allow architecture-specific pci_remap_iospace()

PCI: Allow architecture-specific pci_remap_iospace()

pci_remap_iospace() was originally meant as an architecture specific helper
but it moved into generic code after all architectures had the same
requirements. MIPS has different requirements so it should not be shared.

The way for doing this will be using a macro 'pci_remap_iospace' defined
for those architectures that need a special treatment. Hence, put core API
function inside preprocesor conditional code for 'pci_remap_iospace'
definition.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20210925203224.10419-5-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>