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/purl/default.nix

@@ -0,0 +1,37 @@
+{ lib
+, buildPythonPackage
+, fetchFromGitHub
+, six
+, pytestCheckHook
+}:
+
+buildPythonPackage rec {
+  pname = "purl";
+  version = "1.6";
+
+  src = fetchFromGitHub {
+    owner = "codeinthehole";
+    repo = "purl";
+    rev = version;
+    sha256 = "sha256-Jb3JRW/PtQ7NlO4eQ9DmTPu/sjvFTg2mztphoIF79gc=";
+  };
+
+  propagatedBuildInputs = [
+    six
+  ];
+
+  checkInputs = [
+    pytestCheckHook
+  ];
+
+  pythonImportsCheck = [
+    "purl"
+  ];
+
+  meta = with lib; {
+    description = "Immutable URL class for easy URL-building and manipulation";
+    homepage = "https://github.com/codeinthehole/purl";
+    license = licenses.mit;
+    maintainers = with maintainers; [ jonringer ];
+  };
+}