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/hardware/usbrelayd.nix

@@ -0,0 +1,47 @@
+{ config, lib, pkgs, ... }:
+with lib;
+let
+  cfg = config.services.usbrelayd;
+in
+{
+  options.services.usbrelayd = with types; {
+    enable = mkEnableOption "USB Relay MQTT daemon";
+
+    broker = mkOption {
+      type = str;
+      description = "Hostname or IP address of your MQTT Broker.";
+      default = "127.0.0.1";
+      example = [
+        "mqtt"
+        "192.168.1.1"
+      ];
+    };
+
+    clientName = mkOption {
+      type = str;
+      description = "Name, your client connects as.";
+      default = "MyUSBRelay";
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    environment.etc."usbrelayd.conf".text = ''
+      [MQTT]
+      BROKER = ${cfg.broker}
+      CLIENTNAME = ${cfg.clientName}
+    '';
+
+    services.udev.packages = [ pkgs.usbrelayd ];
+    systemd.packages = [ pkgs.usbrelayd ];
+    users.users.usbrelay = {
+      isSystemUser = true;
+      group = "usbrelay";
+    };
+    users.groups.usbrelay = { };
+  };
+
+  meta = {
+    maintainers = with lib.maintainers; [ wentasah ];
+  };
+}