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/libschrift/default.nix

@@ -0,0 +1,28 @@
+{ lib, stdenv, fetchFromGitHub, fetchpatch }:
+
+stdenv.mkDerivation rec {
+  pname = "libschrift";
+  version = "0.10.1";
+
+  src = fetchFromGitHub {
+    owner = "tomolt";
+    repo = pname;
+    rev = "v" + version;
+    sha256 = "0fvji0z6z2al68p07w58l4hc29ds68v71h7z84vxiqhxnsgc0hlv";
+  };
+
+  postPatch = ''
+    substituteInPlace config.mk \
+      --replace "PREFIX = /usr/local" "PREFIX = $out"
+  '';
+
+  makeFlags = [ "libschrift.a" ];
+
+  meta = with lib; {
+    homepage = "https://github.com/tomolt/libschrift";
+    description = "A lightweight TrueType font rendering library";
+    license = licenses.isc;
+    platforms = platforms.all;
+    maintainers = [ maintainers.sternenseemann ];
+  };
+}