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/libao/default.nix

@@ -0,0 +1,42 @@
+{ stdenv, lib, fetchFromGitHub, autoreconfHook, pkg-config, libpulseaudio, alsa-lib, libcap
+, CoreAudio, CoreServices, AudioUnit
+, usePulseAudio }:
+
+stdenv.mkDerivation rec {
+  version = "1.2.2";
+  pname = "libao";
+
+  # the github mirror is more up to date than downloads.xiph.org
+  src = fetchFromGitHub {
+    owner  = "xiph";
+    repo   = "libao";
+    rev    = version;
+    sha256 = "0svgk4sc9kdhcsfyvbvgm5vpbg3sfr6z5rliflrw49v3x2i4vxq5";
+  };
+
+  configureFlags = [
+    "--disable-broken-oss"
+    "--enable-alsa-mmap"
+  ];
+
+  outputs = [ "out" "dev" "man" "doc" ];
+
+  buildInputs = [ ] ++
+    lib.optional  usePulseAudio   libpulseaudio ++
+    lib.optionals stdenv.isLinux  [ alsa-lib libcap ] ++
+    lib.optionals stdenv.isDarwin [ CoreAudio CoreServices AudioUnit ];
+
+  nativeBuildInputs = [ autoreconfHook pkg-config ];
+
+  meta = with lib; {
+    longDescription = ''
+      Libao is Xiph.org's cross-platform audio library that allows
+      programs to output audio using a simple API on a wide variety of
+      platforms.
+    '';
+    homepage = "https://xiph.org/ao/";
+    license = licenses.gpl2;
+    maintainers = with maintainers; [ ];
+    platforms = with platforms; unix;
+  };
+}