virtio: remove config.c

Remove unused file config.c
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/config.c

-/* Configuration space parsing helpers for virtio.
- *
- * The configuration is [type][len][... len bytes ...] fields.
- *
- * Copyright 2007 Rusty Russell, IBM Corporation.
- * GPL v2 or later.
- */
-#include <linux/err.h>
-#include <linux/virtio.h>
-#include <linux/virtio_config.h>
-#include <linux/bug.h>
-