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/text/diffutils/default.nix

@@ -0,0 +1,35 @@
+{ lib, stdenv, fetchurl, xz, coreutils ? null }:
+
+# 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.
+
+stdenv.mkDerivation rec {
+  pname = "diffutils";
+  version = "3.8";
+
+  src = fetchurl {
+    url = "mirror://gnu/diffutils/diffutils-${version}.tar.xz";
+    sha256 = "sha256-pr3X0bMSZtEcT03mwbdI1GB6sCMa9RiPwlM9CuJDj+w=";
+  };
+
+  outputs = [ "out" "info" ];
+
+  nativeBuildInputs = [ xz.bin ];
+  /* If no explicit coreutils is given, use the one from stdenv. */
+  buildInputs = [ coreutils ];
+
+  configureFlags =
+    # "pr" need not be on the PATH as a run-time dep, so we need to tell
+    # configure where it is. Covers the cross and native case alike.
+    lib.optional (coreutils != null) "PR_PROGRAM=${coreutils}/bin/pr"
+    ++ lib.optional (stdenv.buildPlatform != stdenv.hostPlatform) "gl_cv_func_getopt_gnu=yes";
+
+  meta = with lib; {
+    homepage = "https://www.gnu.org/software/diffutils/diffutils.html";
+    description = "Commands for showing the differences between files (diff, cmp, etc.)";
+    license = licenses.gpl3;
+    platforms = platforms.unix;
+  };
+}