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/keystone/default.nix

@@ -0,0 +1,38 @@
+{ lib, stdenv
+, fetchFromGitHub
+, pkg-config
+, cmake
+, python3
+}:
+
+stdenv.mkDerivation rec {
+  pname = "keystone";
+  version = "0.9.2";
+
+  src = fetchFromGitHub {
+    owner = "keystone-engine";
+    repo = pname;
+    rev = version;
+    sha256 = "020d1l1aqb82g36l8lyfn2j8c660mm6sh1nl4haiykwgdl9xnxfa";
+  };
+
+  cmakeFlags = [
+    "-DBUILD_SHARED_LIBS=ON"
+    "-DCMAKE_INSTALL_LIBDIR=lib"
+  ];
+
+  nativeBuildInputs = [
+    pkg-config
+    cmake
+    python3
+  ];
+
+  meta = with lib; {
+    description = "Lightweight multi-platform, multi-architecture assembler framework";
+    homepage = "https://www.keystone-engine.org";
+    license = licenses.gpl2Only;
+    maintainers = with maintainers; [ luc65r ];
+    mainProgram = "kstool";
+    platforms = platforms.unix;
+  };
+}