virtio: remove kernel virtio header dependencies

Type: refactor

tap, virtio and vhost use virtio/vhost header files from linux
kernel. Different features are supported on different kernel
versions, making it difficult to use those in VPP. This patch
removes virtio/vhost based header dependencies to local header
files.

Change-Id: I064a8adb5cd9753c986b6f224bb075200b3856af
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
diff --git a/src/vnet/devices/virtio/virtio_pci_modern.c b/src/vnet/devices/virtio/virtio_pci_modern.c
index 24e8a4f..0d86ff2 100644
--- a/src/vnet/devices/virtio/virtio_pci_modern.c
+++ b/src/vnet/devices/virtio/virtio_pci_modern.c
@@ -267,7 +267,7 @@
 virtio_pci_modern_setup_queue (vlib_main_t * vm, virtio_if_t * vif,
 			       u16 queue_id, void *p)
 {
-  struct vring vr;
+  vring_t vr;
   u16 queue_size = 0;
 
   virtio_pci_modern_set_queue_select (vif, queue_id);