ARM: integrator: use fixed PCI i/o mapping

Move integrator PCI to fixed i/o mapping and remove io.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>