ARM: make mach/io.h include optional

ARM: make mach/io.h include optional

Add a kconfig option NEED_MACH_IO_H to conditionally include mach/io.h.

Basing this on CONFIG_PCI and CONFIG_ISA doesn't quite work. Most ISA
platforms don't need mach/io.h, but ebsa110 does. Most PCI platforms need
mach/io.h for now, but ks8695 doesn't which means i/o accesses are broken.

Signed-off-by: Rob Herring <[email protected]>
Cc: Russell King <[email protected]>
Acked-by: H Hartley Sweeten <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>