vmm: config: Move TDX to rely on PayloadConfig

Removing the option --tdx to specify that we want to run a TD VM. Rely
on --platform option by adding the "tdx" boolean parameter. This is the
new way for enabling TDX with Cloud Hypervisor.

Along with this change, the way to retrieve the firmware path has been
updated to rely on the recently introduced PayloadConfig structure.

Fixes #4556

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

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

@@ -559,8 +559,6 @@ components:
           type: array
           items:
             $ref: "#/components/schemas/SgxEpcConfig"
-        tdx:
-          $ref: "#/components/schemas/TdxConfig"
         numa:
           type: array
           items:
@@ -650,6 +648,9 @@ components:
           type: array
           items:
             type: string
+        tdx:
+          type: boolean
+          default: false
 
     MemoryZoneConfig:
       required:
@@ -1006,15 +1007,6 @@ components:
           type: boolean
           default: false
 
-    TdxConfig:
-      required:
-        - firmware
-      type: object
-      properties:
-        firmware:
-          type: string
-          description: Path to the firmware that will be used to boot the TDx guest up.
-
     NumaDistance:
       required:
         - destination