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/tools/misc/convimg/default.nix

@@ -0,0 +1,43 @@
+{ lib, stdenv
+, fetchFromGitHub
+}:
+
+stdenv.mkDerivation rec {
+  pname = "convimg";
+  version = "8.9";
+
+  src = fetchFromGitHub {
+    owner = "mateoconlechuga";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "sha256-JTKyOjeiu6FAUrDPDAwLBVgZwmNY11wHonqEV1ukRpw=";
+    fetchSubmodules = true;
+  };
+
+  makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
+
+  checkPhase = ''
+    pushd test
+    patchShebangs test.sh
+    ./test.sh
+    popd
+  '';
+
+  doCheck = true;
+
+  installPhase = ''
+    install -Dm755 bin/convimg $out/bin/convimg
+  '';
+
+  meta = with lib; {
+    description = "Image palette quantization";
+    longDescription = ''
+      This program is used to convert images to other formats,
+      specifically for the TI84+CE and related calculators.
+    '';
+    homepage = "https://github.com/mateoconlechuga/convimg";
+    license = licenses.bsd3;
+    maintainers = with maintainers; [ luc65r ];
+    platforms = platforms.linux;
+  };
+}