virtio: add support for tx-queue-size

Type: improvement

DBGvpp# set loggin class virtio level debug
DBGvpp# create int virtio 0000:00:03.0 tx-queue-size 1024

show virtio pci
```
  Virtqueue (TX) 1
    qsz 1024, last_used_idx 0, desc_next 0, desc_in_use 0
    avail.flags 0x1 avail.idx 0 used.flags 0x0 used.idx 0
```

show logging
```
2022/07/22 23:20:22:557 debug      virtio         0000:00:03.0: tx-queue: number 1, default-size 256
2022/07/22 23:20:22:557 debug      virtio         0000:00:03.0: tx-queue: number 1, new size 1024
```

Change-Id: Ib1a3ebe742b3a6c9fe72bd1c5accfe07682cbdd1
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
diff --git a/src/vnet/devices/virtio/FEATURE.yaml b/src/vnet/devices/virtio/FEATURE.yaml
index 5f4de20..446a45b 100644
--- a/src/vnet/devices/virtio/FEATURE.yaml
+++ b/src/vnet/devices/virtio/FEATURE.yaml
@@ -11,6 +11,8 @@
   - Support multi-queue, GSO, checksum offload, indirect descriptor,
     jumbo frame, and packed ring.
   - Support virtio 1.1 packed ring in vhost
+  - Support for tx queue size configuration (tested on host kernel 5.15
+    and qemu version 6.2.0)
 description: "Virtio implementation"
 missing:
   - API dump filtering by sw_if_index