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/applications/science/robotics/mavproxy/default.nix

@@ -0,0 +1,36 @@
+{ stdenv, lib, buildPythonApplication, fetchPypi, matplotlib, numpy, pymavlink, pyserial
+, setuptools, wxPython_4_0, billiard, gnureadline }:
+
+buildPythonApplication rec {
+  pname = "MAVProxy";
+  version = "1.8.50";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "sha256-dTdXmhm6sWZphLhcoKRDQ2Ir0hcu0ev0xCul2O9hAXg=";
+  };
+
+  postPatch = ''
+    substituteInPlace setup.py \
+      --replace "opencv-python" ""
+  '';
+
+  propagatedBuildInputs = [
+    matplotlib
+    numpy
+    pymavlink
+    pyserial
+    setuptools
+    wxPython_4_0
+  ] ++ lib.optionals stdenv.isDarwin [ billiard gnureadline ];
+
+  # No tests
+  doCheck = false;
+
+  meta = with lib; {
+    description = "MAVLink proxy and command line ground station";
+    homepage = "https://github.com/ArduPilot/MAVProxy";
+    license = licenses.gpl3Plus;
+    maintainers = with maintainers; [ lopsided98 ];
+  };
+}