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/shells/oksh/default.nix

@@ -0,0 +1,33 @@
+{ stdenv, lib, fetchFromGitHub, buildPackages }:
+
+stdenv.mkDerivation rec {
+  pname = "oksh";
+  version = "7.0";
+
+  src = fetchFromGitHub {
+    owner = "ibara";
+    repo = pname;
+    rev = "${pname}-${version}";
+    sha256 = "sha256-076nD0aPps6n5qkR3LQJ6Kn2g3mkov+/M0qSvxNLZ6o=";
+  };
+
+  strictDeps = true;
+
+  postPatch = lib.optionalString (stdenv.buildPlatform != stdenv.hostPlatform) ''
+    substituteInPlace configure --replace "./conftest" "echo"
+  '';
+
+  configureFlags = [ "--no-strip" ];
+
+  meta = with lib; {
+    description = "Portable OpenBSD ksh, based on the Public Domain Korn Shell (pdksh)";
+    homepage = "https://github.com/ibara/oksh";
+    license = licenses.publicDomain;
+    maintainers = with maintainers; [ siraben ];
+    platforms = platforms.all;
+  };
+
+  passthru = {
+    shellPath = "/bin/oksh";
+  };
+}