MIPS: implement architecture-specific 'pci_remap_iospace()'

MIPS: implement architecture-specific 'pci_remap_iospace()'

To make PCI IO work we need to properly virtually map IO cpu physical address
and set this virtual address as the address of the first PCI IO port which
is set using function 'set_io_port_base()'.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20210925203224.10419-6-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>