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/data/machine-learning/mnist/default.nix

@@ -0,0 +1,45 @@
+{ lib, stdenvNoCC, fetchurl }:
+let
+  srcs = {
+    train-images = fetchurl {
+      url = "http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz";
+      sha256 = "029na81z5a1c9l1a8472dgshami6f2iixs3m2ji6ym6cffzwl3s4";
+    };
+    train-labels = fetchurl {
+      url = "http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz";
+      sha256 = "0p152200wwx0w65sqb65grb3v8ncjp230aykmvbbx2sm19556lim";
+    };
+    test-images = fetchurl {
+      url = "http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz";
+      sha256 = "1rn4vfigaxn2ms24bf4jwzzflgp3hvz0gksvb8j7j70w19xjqhld";
+    };
+    test-labels = fetchurl {
+      url = "http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz";
+      sha256 = "1imf0i194ndjxzxdx87zlgn728xx3p1qhq1ssbmnvv005vwn1bpp";
+    };
+  };
+in
+  stdenvNoCC.mkDerivation rec {
+    pname = "mnist";
+    version = "2018-11-16";
+    installPhase = ''
+      mkdir -p $out
+      ln -s "${srcs.train-images}" "$out/${srcs.train-images.name}"
+      ln -s "${srcs.train-labels}" "$out/${srcs.train-labels.name}"
+      ln -s "${srcs.test-images}" "$out/${srcs.test-images.name}"
+      ln -s "${srcs.test-labels}" "$out/${srcs.test-labels.name}"
+    '';
+    dontUnpack = true;
+    meta = with lib; {
+      description = "A large database of handwritten digits";
+      longDescription = ''
+        The MNIST database (Modified National Institute of Standards and
+        Technology database) is a large database of handwritten digits that is
+        commonly used for training various image processing systems.
+      '';
+      homepage = "http://yann.lecun.com/exdb/mnist/index.html";
+      license = licenses.cc-by-sa-30;
+      platforms = platforms.all;
+      maintainers = with maintainers; [ cmcdragonkai ];
+    };
+  }