nios2: remove include asm-generic/iomap.h from io.h
nios2: remove include asm-generic/iomap.h from io.h

Don't need asm-generic/iomap.h and asm-generic/io.h added
default ioread8/16/32 iowrite8/16/32 implementation.

Signed-off-by: Ley Foon Tan <95f178e5e278816be0436ff61f034a97684bdd0e@altera.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs