vhost: fix missing include

Add a missing include with the defines for vhost-user driver features.

Fixes: 5fbb394 ("vhost: introduce driver features related APIs")
Cc: stable@dpdk.org

Signed-off-by: Noa Ezra <noae@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Matan Azrad <matan@mellanox.com>

lib/librte_vhost/rte_vhost.h

@@ -23,6 +23,7 @@ extern "C" {
 /* These are not C++-aware. */
 #include <linux/vhost.h>
 #include <linux/virtio_ring.h>
+#include <linux/virtio_net.h>
 
 #define RTE_VHOST_USER_CLIENT		(1ULL << 0)
 #define RTE_VHOST_USER_NO_RECONNECT	(1ULL << 1)