refactor(luks): use system_cfg.luks directly across roles

roles/virtualization/defaults/main.yml

@@ -15,10 +15,10 @@ virtualization_xen_disk_path: /var/lib/xen/images
 
 virtualization_tpm2_enabled: >-
   {{
-    (partitioning_luks_enabled | bool)
-    and (partitioning_luks_auto_decrypt | bool)
+    (system_cfg.luks.enabled | bool)
+    and (system_cfg.luks.auto | bool)
     and (
-      (partitioning_luks_auto_decrypt_method | lower)
+      (system_cfg.luks.method | lower)
       == 'tpm2'
     )
   }}