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/kexec.nix

@@ -0,0 +1,50 @@
+import ./make-test-python.nix ({ pkgs, lib, ... }: {
+  name = "kexec";
+  meta = with lib.maintainers; {
+    maintainers = [ flokli lassulus ];
+  };
+
+  nodes = {
+    node1 = { ... }: {
+      virtualisation.vlans = [ ];
+      virtualisation.memorySize = 4 * 1024;
+      virtualisation.useBootLoader = true;
+      virtualisation.useEFIBoot = true;
+      boot.loader.systemd-boot.enable = true;
+      boot.loader.efi.canTouchEfiVariables = true;
+    };
+
+    node2 = { modulesPath, ... }: {
+      virtualisation.vlans = [ ];
+      environment.systemPackages = [ pkgs.hello ];
+      imports = [
+        "${modulesPath}/installer/kexec/kexec-boot.nix"
+        "${modulesPath}/profiles/minimal.nix"
+      ];
+    };
+  };
+
+  testScript = { nodes, ... }: ''
+    # Test whether reboot via kexec works.
+    node1.wait_for_unit("multi-user.target")
+    node1.succeed('kexec --load /run/current-system/kernel --initrd /run/current-system/initrd --command-line "$(</proc/cmdline)"')
+    node1.execute("systemctl kexec >&2 &", check_return=False)
+    node1.connected = False
+    node1.connect()
+    node1.wait_for_unit("multi-user.target")
+
+    # Check if the machine with kexec-boot.nix profile boots up
+    node2.wait_for_unit("multi-user.target")
+    node2.shutdown()
+
+    # Kexec node1 to the toplevel of node2 via the kexec-boot script
+    node1.succeed('touch /run/foo')
+    node1.fail('hello')
+    node1.execute('${nodes.node2.config.system.build.kexecBoot}/kexec-boot', check_return=False)
+    node1.succeed('! test -e /run/foo')
+    node1.succeed('hello')
+    node1.succeed('[ "$(hostname)" = "node2" ]')
+
+    node1.shutdown()
+  '';
+})