vmm: Make desired vCPUs optional in resize command

In order to be able to support resizing either vCPUs or memory or both
make the fields in the resize command optional.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vmm/src/api/mod.rs

@@ -115,7 +115,7 @@ pub struct VmmPingResponse {
 
 #[derive(Clone, Deserialize, Serialize)]
 pub struct VmResizeData {
-    pub desired_vcpus: u8,
+    pub desired_vcpus: Option<u8>,
 }
 
 pub enum ApiResponsePayload {

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

@@ -427,11 +427,8 @@ components:
           default: false
 
     VmResize:
-      required:
-      - desired_vcpus
       type: object
       properties:
         desired_vcpus:
           minimum: 1
-          default: 1
           type: integer