tests/vmm_x86: need to request platform_info direct from core

tests/vmm_x86.nix

@@ -6,6 +6,7 @@
   machine = { pkgs, ... }: {
     genode.init.children.vmm = {
       configFile = ./vmm_x86.dhall;
+      coreROMs = [ "platform_info" ];
       inputs = with pkgs.genodePackages; [ test-vmm_x86 ];
     };
   };