ARM: io: remove IO_SPACE_LIMIT from SA11x0

SA11x0 only uses IO_SPACE_LIMIT for SOC_COMMON, so we can use the
default value in asm/io.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-sa1100/include/mach/io.h

@@ -10,11 +10,9 @@
 #ifndef __ASM_ARM_ARCH_IO_H
 #define __ASM_ARM_ARCH_IO_H
 
-#define IO_SPACE_LIMIT 0xffffffff
-
 /*
- * We don't actually have real ISA nor PCI buses, but there is so many 
- * drivers out there that might just work if we fake them...
+ * __io() is required to be an equivalent mapping to __mem_pci() for
+ * SOC_COMMON to work.
  */
 #define __io(a)		__typesafe_io(a)
 #define __mem_pci(a)	(a)