Move the VIRTIO_RING_F_* defines out of virtqueue.h into virtio_config.h

These defines are applicable to userland too, but virtqueue.h contains
the kernel virtqueue interface, and is therefore not usable in userland.

Note that Linux places these defines in virtio_ring.h, but I don't want
the drivers including this header file to keep the VirtIO ring opaque to
everything but the virtqueue.

MFC after:	1 week

sys/dev/virtio/pci/virtio_pci.c

@@ -45,7 +45,6 @@ __FBSDID("$FreeBSD$");
 #include <dev/pci/pcireg.h>
 
 #include <dev/virtio/virtio.h>
-#include <dev/virtio/virtio_config.h>
 #include <dev/virtio/virtqueue.h>
 #include <dev/virtio/pci/virtio_pci.h>
 

sys/dev/virtio/virtio.h

@@ -30,6 +30,7 @@
 #define _VIRTIO_H_
 
 #include <dev/virtio/virtio_ids.h>
+#include <dev/virtio/virtio_config.h>
 
 struct vq_alloc_info;
 

sys/dev/virtio/virtio_config.h

@@ -44,6 +44,12 @@
  */
 #define VIRTIO_F_NOTIFY_ON_EMPTY (1 << 24)
 
+/* Support for indirect buffer descriptors. */
+#define VIRTIO_RING_F_INDIRECT_DESC	(1 << 28)
+
+/* Support to suppress interrupt until specific index is reached. */
+#define VIRTIO_RING_F_EVENT_IDX		(1 << 29)
+
 /*
  * The guest should never negotiate this feature; it
  * is used to detect faulty drivers.

sys/dev/virtio/virtqueue.c

@@ -48,7 +48,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/rman.h>
 
 #include <dev/virtio/virtio.h>
-#include <dev/virtio/virtio_config.h>
 #include <dev/virtio/virtqueue.h>
 #include <dev/virtio/virtio_ring.h>
 

sys/dev/virtio/virtqueue.h

@@ -32,12 +32,6 @@
 struct virtqueue;
 struct sglist;
 
-/* Support for indirect buffer descriptors. */
-#define VIRTIO_RING_F_INDIRECT_DESC	(1 << 28)
-
-/* Support to suppress interrupt until specific index is reached. */
-#define VIRTIO_RING_F_EVENT_IDX		(1 << 29)
-
 /* Device callback for a virtqueue interrupt. */
 typedef void virtqueue_intr_t(void *);