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/tools/misc/bashcards/default.nix

@@ -0,0 +1,30 @@
+{ lib, stdenv
+, fetchFromGitHub
+}:
+
+stdenv.mkDerivation rec {
+  pname = "bashcards";
+  version = "0.1.3";
+
+  src = fetchFromGitHub {
+    owner = "rpearce";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "1rpqrh0022sbrjvd55a0jvpdqhhka5msf8dsz6adbbmxy3xzgdid";
+  };
+
+  dontBuild = true;
+  installPhase = ''
+    mkdir -p $out/bin $out/share/man/man8
+    cp bashcards.8 $out/share/man/man8/
+    cp bashcards $out/bin/
+  '';
+
+  meta = with lib; {
+    description = "Practice flashcards in bash";
+    homepage = "https://github.com/rpearce/bashcards/";
+    license = licenses.bsd3;
+    maintainers = with maintainers; [ rpearce ];
+    platforms = platforms.all;
+  };
+}