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/rxe.nix

@@ -0,0 +1,47 @@
+import ./make-test-python.nix ({ ... } :
+
+let
+  node = { pkgs, ... } : {
+    networking = {
+      firewall = {
+        allowedUDPPorts = [ 4791 ]; # open RoCE port
+        allowedTCPPorts = [ 4800 ]; # port for test utils
+      };
+      rxe = {
+        enable = true;
+        interfaces = [ "eth1" ];
+      };
+    };
+
+    environment.systemPackages = with pkgs; [ rdma-core screen ];
+  };
+
+in {
+  name = "rxe";
+
+  nodes = {
+    server = node;
+    client = node;
+  };
+
+  testScript = ''
+    # Test if rxe interface comes up
+    server.wait_for_unit("default.target")
+    server.succeed("systemctl status rxe.service")
+    server.succeed("ibv_devices | grep rxe_eth1")
+
+    client.wait_for_unit("default.target")
+
+    # ping pong tests
+    for proto in "rc", "uc", "ud", "srq":
+        server.succeed(
+            "screen -dmS {0}_pingpong ibv_{0}_pingpong -p 4800 -s 1024 -g0".format(proto)
+        )
+        client.succeed("sleep 2; ibv_{}_pingpong -p 4800 -s 1024 -g0 server".format(proto))
+
+    server.succeed("screen -dmS rping rping -s -a server -C 10")
+    client.succeed("sleep 2; rping -c -a server -C 10")
+  '';
+})
+
+