ARM: fix __io macro for PCMCIA

With commit c334bc15 (ARM: make mach/io.h include optional), PCMCIA was
broken. PCMCIA depends on __io() returning a valid i/o address, and most
ARM platforms require IO_SPACE_LIMIT be set to 0xffffffff for PCMCIA. This
needs a better fix with a fixed i/o address mapping, but for now we just
restore things to the previous behavior.

This fixes at91, omap1, pxa and sa11xx. pxa needs io.h if PCI is enabled,
but PCMCIA is not. sa11xx already has IO_SPACE_LIMIT set to 0xffffffff,
so it doesn't need an io.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Joachim Eastwood <joachim.eastwood@jotron.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Tested-by: Paul Parsons <lost.distance@yahoo.com> (pxa270)
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Olof Johansson <olof@lixom.net>