parisc: Remove memcpy_toio and memset_io

Recently new functions for IO memcpy and IO memset were added in
libs/iomem_copy.c. So, remove the arch specific implementations, to fall
back to the generic ones which do exactly the same. Keep memcpy_fromio
for now, because it's slight more optimized by doing 'u16' accesses if
the buffer is aligned this way.

Signed-off-by: Julian Vetter <julian@outer-limits.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>