Update compute.json to include hyperVGeneration property for VirtualMachineInstanceView (#6367)

Adds hyperVGeneration  which displays what HyperVisor Generation the VM Boots in, via the VirtualMachineInstanceView.

Author: srvar

specification/compute/resource-manager/Microsoft.Compute/stable/2019-03-01/compute.json

@@ -6410,6 +6410,18 @@
           "type": "string",
           "description": "The version of Operating System running on the virtual machine."
         },
+        "hyperVGeneration": {
+          "type": "string",
+          "description": "Specifies the HyperVGeneration Type associated with a resource",
+          "enum": [
+            "V1",
+            "V2"
+          ],
+          "x-ms-enum": {
+            "name": "HyperVGenerationType",
+            "modelAsString": true
+          }
+        },
         "rdpThumbPrint": {
           "type": "string",
           "description": "The Remote desktop certificate thumbprint."