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/archivers/rpm2targz/default.nix

@@ -0,0 +1,50 @@
+{ bzip2
+, coreutils
+, cpio
+, fetchurl
+, gnutar
+, gzip
+, lib
+, stdenv
+, xz
+, zstd
+}:
+
+stdenv.mkDerivation rec {
+  pname = "rpm2targz";
+  version = "2021.03.16";
+
+  # git repo: https://gitweb.gentoo.org/proj/rpm2targz.git/
+  src = fetchurl {
+    url = "https://dev.gentoo.org/~vapier/dist/${pname}-${version}.tar.xz";
+    hash = "sha256-rcV+o9V2wWKznqSW2rA8xgnpQ02kpK4te6mYvLRC5vQ=";
+  };
+
+  postPatch = let
+    shdeps = [
+      bzip2
+      coreutils
+      cpio
+      gnutar
+      gzip
+      xz
+      zstd
+    ];
+  in ''
+    substituteInPlace rpm2targz --replace "=\"rpmoffset\"" "=\"$out/bin/rpmoffset\""
+    # rpm2targz relies on the executable name
+    # to guess what compressor it should use
+    # this is more reliable than wrapProgram
+    sed -i -e '2iexport PATH="${lib.makeBinPath shdeps}"' rpm2targz
+  '';
+
+  installFlags = [ "prefix=$(out)" ];
+
+  meta = with lib; {
+    description = "Convert a .rpm file to a .tar.gz archive";
+    homepage = "http://slackware.com/config/packages.php";
+    license = licenses.bsd1;
+    maintainers = with maintainers; [ zseri ];
+    platforms = platforms.all;
+  };
+}