[PATCH] : Delete obselete hd64461 io.c file

[Kristoffer E. <kri...@gm...>]

Shortlog:
* io.c found in arch/sh/cchips/hd6446x/hd64461/ directory was used to translate PIO -> MMIO. Since we have moved away from PIO this file is useless. 
* All io functions are now handled by generic

signed-off-by: Kristoffer Ericson <Kri...@gm...>