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/fonts/et-book/default.nix

@@ -0,0 +1,22 @@
+{ lib, fetchFromGitHub }:
+
+fetchFromGitHub rec {
+  rev = "7e8f02dadcc23ba42b491b39e5bdf16e7b383031";
+  name = "et-book-${builtins.substring 0 6 rev}";
+  owner = "edwardtufte";
+  repo = "et-book";
+  sha256 = "1bfb1l8k7fzgk2l8cikiyfn5x9m0fiwrnsbc1483p8w3qp58s5n2";
+
+  postFetch = ''
+    tar -xzf $downloadedFile
+    mkdir -p $out/share/fonts/truetype
+    cp -t $out/share/fonts/truetype et-book-${rev}/source/4-ttf/*.ttf
+  '';
+
+  meta = with lib; {
+    description = "The typeface used in Edward Tufte’s books.";
+    license = licenses.mit;
+    platforms = platforms.all;
+    maintainers = with maintainers; [ jethro ];
+  };
+}