virtio-rng: use standard-headers

Drop duplicated code.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>

include/hw/virtio/virtio-rng.h

@@ -14,6 +14,7 @@
 
 #include "sysemu/rng.h"
 #include "sysemu/rng-random.h"
+#include "standard-headers/linux/virtio_rng.h"
 
 #define TYPE_VIRTIO_RNG "virtio-rng-device"
 #define VIRTIO_RNG(obj) \
@@ -21,9 +22,6 @@
 #define VIRTIO_RNG_GET_PARENT_CLASS(obj) \
         OBJECT_GET_PARENT_CLASS(obj, TYPE_VIRTIO_RNG)
 
-/* The Virtio ID for the virtio rng device */
-#define VIRTIO_ID_RNG    4
-
 struct VirtIORNGConf {
     RngBackend *rng;
     uint64_t max_bytes;