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/tests/hydra/default.nix

@@ -0,0 +1,59 @@
+{ system ? builtins.currentSystem
+, config ? { }
+, pkgs ? import ../../.. { inherit system config; }
+}:
+
+with import ../../lib/testing-python.nix { inherit system pkgs; };
+with pkgs.lib;
+
+let
+
+  inherit (import ./common.nix { inherit system; }) baseConfig;
+
+  hydraPkgs = {
+    inherit (pkgs) hydra_unstable;
+  };
+
+  makeHydraTest = with pkgs.lib; name: package: makeTest {
+    name = "hydra-${name}";
+    meta = with pkgs.lib.maintainers; {
+      maintainers = [ lewo ma27 ];
+    };
+
+    nodes.machine = { pkgs, lib, ... }: {
+      imports = [ baseConfig ];
+      services.hydra = { inherit package; };
+    };
+
+    testScript = ''
+      # let the system boot up
+      machine.wait_for_unit("multi-user.target")
+      # test whether the database is running
+      machine.wait_for_unit("postgresql.service")
+      # test whether the actual hydra daemons are running
+      machine.wait_for_unit("hydra-init.service")
+      machine.require_unit_state("hydra-queue-runner.service")
+      machine.require_unit_state("hydra-evaluator.service")
+      machine.require_unit_state("hydra-notify.service")
+
+      machine.succeed("hydra-create-user admin --role admin --password admin")
+
+      # create a project with a trivial job
+      machine.wait_for_open_port(3000)
+
+      # make sure the build as been successfully built
+      machine.succeed("create-trivial-project.sh")
+
+      machine.wait_until_succeeds(
+          'curl -L -s http://localhost:3000/build/1 -H "Accept: application/json" |  jq .buildstatus | xargs test 0 -eq'
+      )
+
+      machine.wait_until_succeeds(
+          'journalctl -eu hydra-notify.service -o cat | grep -q "sending mail notification to hydra@localhost"'
+      )
+    '';
+  };
+
+in
+
+mapAttrs makeHydraTest hydraPkgs