Kill off the hd64461 io.c, as all of the hd64461 users are now
using the generic I/O routines.

[ hd64461/ moved to hd64461.c by Paul ]
Signed-off-by: NKristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>