uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/services/monitoring/das_watchdog.nix

@@ -0,0 +1,34 @@
+# A general watchdog for the linux operating system that should run in the
+# background at all times to ensure a realtime process won't hang the machine
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  inherit (pkgs) das_watchdog;
+
+in {
+  ###### interface
+
+  options = {
+    services.das_watchdog.enable = mkEnableOption "realtime watchdog";
+  };
+
+  ###### implementation
+
+  config = mkIf config.services.das_watchdog.enable {
+    environment.systemPackages = [ das_watchdog ];
+    systemd.services.das_watchdog = {
+      description = "Watchdog to ensure a realtime process won't hang the machine";
+      after = [ "multi-user.target" "sound.target" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        User = "root";
+        Type = "simple";
+        ExecStart = "${das_watchdog}/bin/das_watchdog";
+        RemainAfterExit = true;
+      };
+    };
+  };
+}