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/hardware/brillo.nix

@@ -0,0 +1,22 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  cfg = config.hardware.brillo;
+in
+{
+  options = {
+    hardware.brillo = {
+      enable = mkEnableOption ''
+        Enable brillo in userspace.
+        This will allow brightness control from users in the video group.
+      '';
+    };
+  };
+
+
+  config = mkIf cfg.enable {
+    services.udev.packages = [ pkgs.brillo ];
+    environment.systemPackages = [ pkgs.brillo ];
+  };
+}