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/udatetime/default.nix

@@ -0,0 +1,35 @@
+{ lib
+, buildPythonPackage
+, fetchPypi
+, fetchpatch
+}:
+
+buildPythonPackage rec {
+  pname = "udatetime";
+  version = "0.0.16";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "09vlcskvaxnfk73l9w5xgl2ks9l62g1b24yrm0xxb7gn93qxglw2";
+  };
+
+  patches = [
+    # fix build with python 3.9
+    (fetchpatch {
+      url = "https://github.com/freach/udatetime/pull/33.patch";
+      sha256 = "02wm7ivkv1viqn2wflgd10dgpddfqfrwacmrldigb1mwb79n554j";
+    })
+  ];
+
+  # tests not included on pypi
+  doCheck = false;
+
+  pythonImportsCheck = [ "udatetime" ];
+
+  meta = with lib; {
+    description = "Fast RFC3339 compliant Python date-time library";
+    homepage = "https://github.com/freach/udatetime";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ globin ];
+  };
+}