linux: build with SCHEDUTIL governor

- it can't be built as a module
- it's not set as the default yet
- for discussion see https://github.com/NixOS/nixpkgs/pull/42330

pkgs/os-specific/linux/kernel/common-config.nix

@@ -61,6 +61,7 @@ let
       X86_INTEL_PSTATE                 = yes;
       INTEL_IDLE                       = yes;
       CPU_FREQ_DEFAULT_GOV_PERFORMANCE = yes;
+      CPU_FREQ_GOV_SCHEDUTIL           = whenAtLeast "4.9" yes;
       PM_WAKELOCKS                     = yes;
     };