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/misc/hexd/default.nix

@@ -0,0 +1,25 @@
+{ lib, stdenv, fetchFromGitHub }:
+
+with lib;
+
+stdenv.mkDerivation rec {
+  pname = "hexd";
+  version = "1.1.0";
+
+  src = fetchFromGitHub {
+    owner = "FireyFly";
+    repo = "hexd";
+    rev = "v${version}";
+    sha256 = "sha256-b/dROBQVPEiMBTcu4MTi6Lf6ChkFZqZrJ1V0j54rrFY=";
+  };
+
+  makeFlags = [ "PREFIX=$(out)" ];
+
+  meta = {
+    description = "Colourful, human-friendly hexdump tool";
+    homepage = "https://github.com/FireyFly/hexd";
+    maintainers = [ maintainers.FireyFly ];
+    license = licenses.mit;
+    platforms = platforms.unix;
+  };
+}