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/python-modules/pdfx/default.nix

@@ -0,0 +1,30 @@
+{ lib, buildPythonPackage, fetchFromGitHub, pdfminer-six, chardet, pytestCheckHook }:
+
+buildPythonPackage rec {
+  pname = "pdfx";
+  version = "1.4.1";
+
+  src = fetchFromGitHub {
+    owner = "metachris";
+    repo = "pdfx";
+    rev = "v${version}";
+    sha256 = "sha256-POpP6XwcqwvImrtIiDjpnHoNE0MKapuPjxojo+ocBK0=";
+  };
+
+  postPatch = ''
+    substituteInPlace requirements.txt \
+      --replace "chardet==4.0.0" "chardet" \
+      --replace "pdfminer.six==20201018" "pdfminer.six"
+  '';
+
+  propagatedBuildInputs = [ pdfminer-six chardet ];
+
+  checkInputs = [ pytestCheckHook ];
+
+  meta = with lib; {
+    inherit (src.meta) homepage;
+    description = "Extract references (pdf, url, doi, arxiv) and metadata from a PDF";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ marsam ];
+  };
+}