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/math/bcal/default.nix

@@ -0,0 +1,37 @@
+{ lib
+, stdenv
+, fetchFromGitHub
+, readline
+, bc
+, python3Packages
+}:
+
+stdenv.mkDerivation rec {
+  pname = "bcal";
+  version = "2.4";
+
+  src = fetchFromGitHub {
+    owner = "jarun";
+    repo = "bcal";
+    rev = "v${version}";
+    sha256 = "sha256-PleWU2yyJzkUAZEvEYoCGdpEXqOgRvZK9zXTYrxRtQU=";
+  };
+
+  buildInputs = [ readline ];
+
+  installFlags = [ "PREFIX=$(out)" ];
+
+  doCheck = true;
+
+  checkInputs = [ bc python3Packages.pytestCheckHook ];
+
+  pytestFlagsArray = [ "test.py" ];
+
+  meta = with lib; {
+    description = "Storage conversion and expression calculator";
+    homepage = "https://github.com/jarun/bcal";
+    license = licenses.gpl3Only;
+    platforms = platforms.unix;
+    maintainers = with maintainers; [ jfrankenau ];
+  };
+}