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/x11/xfs.nix

@@ -0,0 +1,46 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  configFile = ./xfs.conf;
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.xfs = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to enable the X Font Server.";
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf config.services.xfs.enable {
+    assertions = singleton
+      { assertion = config.fonts.enableFontDir;
+        message = "Please enable fonts.enableFontDir to use the X Font Server.";
+      };
+
+    systemd.services.xfs = {
+      description = "X Font Server";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      path = [ pkgs.xorg.xfs ];
+      script = "xfs -config ${configFile}";
+    };
+  };
+}