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/tigervnc.nix

@@ -0,0 +1,53 @@
+{ system ? builtins.currentSystem
+, config ? {}
+, pkgs ? import ../.. { inherit system config; }
+}:
+
+with import ../lib/testing-python.nix { inherit system pkgs; };
+makeTest {
+  name = "tigervnc";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ lheckemann ];
+  };
+
+  nodes = {
+    server = { pkgs, ...}: {
+      environment.systemPackages = with pkgs; [
+        tigervnc # for Xvnc
+        xorg.xwininfo
+        imagemagickBig # for display with working label: support
+      ];
+      networking.firewall.allowedTCPPorts = [ 5901 ];
+    };
+
+    client = { pkgs, ... }: {
+      imports = [ ./common/x11.nix ];
+      # for vncviewer
+      environment.systemPackages = [ pkgs.tigervnc ];
+    };
+  };
+
+  enableOCR = true;
+
+  testScript = ''
+    start_all()
+
+    for host in [server, client]:
+        host.succeed("echo foobar | vncpasswd -f > vncpasswd")
+
+    server.succeed("Xvnc -geometry 720x576 :1 -PasswordFile vncpasswd >&2 &")
+    server.wait_until_succeeds("nc -z localhost 5901", timeout=10)
+    server.succeed("DISPLAY=:1 xwininfo -root | grep 720x576")
+    server.execute("DISPLAY=:1 display -size 360x200 -font sans -gravity south label:'HELLO VNC WORLD' >&2 &")
+
+    client.wait_for_x()
+    client.execute("vncviewer server:1 -PasswordFile vncpasswd >&2 &")
+    client.wait_for_window(r"VNC")
+    client.screenshot("screenshot")
+    text = client.get_screen_text()
+    # Displayed text
+    assert 'HELLO VNC WORLD' in text
+    # Client window title
+    assert 'TigerVNC' in text
+  '';
+}