Staging: kpc2000: kpc_dma: include <linux/io.h> instead of <asm/io.h>

Fix following checkpatch.pl warning by including
<linux/io.h> instead of <asm/io.h>.

WARNING: Use #include <linux/io.h> instead of <asm/io.h>

Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>