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/development/libraries/libidn2/default.nix

@@ -0,0 +1,49 @@
+{ fetchurl, lib, stdenv, libiconv, libunistring, help2man, texinfo, buildPackages }:
+
+# Note: this package is used for bootstrapping fetchurl, and thus
+# cannot use fetchpatch! All mutable patches (generated by GitHub or
+# cgit) that are needed here should be included directly in Nixpkgs as
+# files.
+
+with lib;
+
+stdenv.mkDerivation rec {
+  pname = "libidn2";
+  version = "2.3.2";
+
+  src = fetchurl {
+    url = "mirror://gnu/gnu/libidn/${pname}-${version}.tar.gz";
+    sha256 = "sha256-dpQM1Od46Ak1eanRlbJf/16Tbp3GJCBoUotDenZ2T5E=";
+  };
+
+  strictDeps = true;
+  outputs = [ "bin" "dev" "out" "info" "devdoc" ];
+
+  patches = optional stdenv.isDarwin ./fix-error-darwin.patch;
+
+  enableParallelBuilding = true;
+
+  # The above patch causes the documentation to be regenerated, so the
+  # documentation tools are required.
+  nativeBuildInputs = optionals stdenv.isDarwin [ help2man texinfo ];
+  buildInputs = [ libunistring ] ++ optional stdenv.isDarwin libiconv;
+  depsBuildBuild = [ buildPackages.stdenv.cc ];
+
+  meta = {
+    homepage = "https://www.gnu.org/software/libidn/#libidn2";
+    description = "Free software implementation of IDNA2008 and TR46";
+
+    longDescription = ''
+      Libidn2 is believed to be a complete IDNA2008 and TR46 implementation,
+      but has yet to be as extensively used as the IDNA2003 Libidn library.
+
+      The installed C library libidn2 is dual-licensed under LGPLv3+|GPLv2+,
+      while the rest of the package is GPLv3+.  See the file COPYING for
+      detailed information.
+    '';
+
+    license = with lib.licenses; [ lgpl3Plus gpl2Plus gpl3Plus ];
+    platforms = lib.platforms.all;
+    maintainers = with lib.maintainers; [ fpletz ];
+  };
+}