vmm: Add multiple queue option and update config for virtio-net device

Add num_queues and queue_size for virtio-net device to make them configurable,
while add the associated options in command line.

Update cloud-hypervisor.yaml with the new options for NetConfig.

Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>

vmm/src/api/openapi/cloud-hypervisor.yaml

@@ -295,6 +295,12 @@ components:
         iommu:
           type: boolean
           default: false
+        num_queues:
+          type: integer
+          default: 2
+        queue_size:
+          type: integer
+          default: 256
 
     RngConfig:
       required: