Since commit 8da3ff18

 ("MMIO callback
interface changes"), the addresses passed to the I/O functions are an
offset to the start of the area. As a consequence, there is no need to
correct the address using the value of IOBR. This make possible the use
of the default MMIO functions. Moreover the addresses are now remaped
when the value if IOBR change.

The memory area corresponds to the devices behing the PCI bus, it should
not be mapped by the PCI controller. Remove the corresponding code.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>