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>

pkgs/tools/networking/corerad/default.nix

@@ -0,0 +1,39 @@
+{ lib, buildGoModule, fetchFromGitHub, nixosTests }:
+
+buildGoModule rec {
+  pname = "corerad";
+  version = "1.2.1";
+
+  src = fetchFromGitHub {
+    owner = "mdlayher";
+    repo = "corerad";
+    rev = "v${version}";
+    sha256 = "sha256-JhdR1UKHnzXIUoe1shb3IZne3q198NLwRROEYuKsnW4=";
+  };
+
+  vendorSha256 = "sha256-w15dRxIBzDN5i4RNEDuSfCHHb4wc4fw1B2wjlTk40iE=";
+
+  # Since the tarball pulled from GitHub doesn't contain git tag information,
+  # we fetch the expected tag's timestamp from a file in the root of the
+  # repository.
+  preBuild = ''
+    buildFlagsArray=(
+      -ldflags="
+        -X github.com/mdlayher/corerad/internal/build.linkTimestamp=$(<.gittagtime)
+        -X github.com/mdlayher/corerad/internal/build.linkVersion=v${version}
+      "
+    )
+  '';
+
+  passthru.tests = {
+    inherit (nixosTests) corerad;
+  };
+
+  meta = with lib; {
+    homepage = "https://github.com/mdlayher/corerad";
+    description = "Extensible and observable IPv6 NDP RA daemon";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ mdlayher ];
+    platforms = platforms.linux;
+  };
+}