include/linux/compat.h: fix warning: preprocessor token {__iomem, __user} redefined

include/linux/compat.h:4:9: warning: preprocessor token __user redefined
include/linux/compiler.h:7:10: this was the original definition
include/linux/compat.h:5:9: warning: preprocessor token __iomem redefined
include/linux/compiler.h:12:10: this was the original definition

fixup __iomem, __user definitions in compat.h code appears to be placed
there as a cover up from a code import from linux when u-boot didn't yet
have a compiler.h, introduced by commit
932394ac "Rewrite of NAND code based on
what is in 2.6.12 Linux kernel".

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>