iop: when scanning PCI bus, translate the PCI addresses according to the outbound window settings

... otherwise we end up trying to access peripherals using wrong PCI
addresses.

Cc: Lennert Buytenhek <kernel@wantstofly.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>