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/libraries/libgit2/default.nix

@@ -0,0 +1,50 @@
+{ lib
+, stdenv
+, fetchFromGitHub
+, cmake
+, pkg-config
+, python3
+, zlib
+, libssh2
+, openssl
+, pcre
+, http-parser
+, libiconv
+, Security
+}:
+
+stdenv.mkDerivation rec {
+  pname = "libgit2";
+  version = "1.4.3";
+  # also check the following packages for updates: python3.pkgs.pygit2 and libgit2-glib
+
+  src = fetchFromGitHub {
+    owner = "libgit2";
+    repo = "libgit2";
+    rev = "v${version}";
+    sha256 = "sha256-WnRzH5uMVEStA5ns4GNgMD5YoLQoats9aPLfnz9RoQs=";
+  };
+
+  cmakeFlags = [
+    "-DTHREADSAFE=ON"
+    "-DUSE_HTTP_PARSER=system"
+    "-DUSE_SSH=ON"
+  ];
+
+  nativeBuildInputs = [ cmake python3 pkg-config ];
+
+  buildInputs = [ zlib libssh2 openssl pcre http-parser ]
+    ++ lib.optional stdenv.isDarwin Security;
+
+  propagatedBuildInputs = lib.optional (!stdenv.isLinux) libiconv;
+
+  doCheck = false; # hangs. or very expensive?
+
+  meta = with lib; {
+    description = "Linkable library implementation of Git that you can use in your application";
+    homepage = "https://libgit2.org/";
+    license = licenses.gpl2Plus;
+    platforms = platforms.all;
+    maintainers = with maintainers; [ SuperSandro2000 ];
+  };
+}