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/filesystems/idsk/default.nix

@@ -0,0 +1,30 @@
+{ lib, stdenv, fetchFromGitHub, cmake }:
+
+stdenv.mkDerivation rec {
+
+  pname = "idsk";
+  version = "0.20";
+
+  src = fetchFromGitHub {
+    repo = "idsk";
+    owner = "cpcsdk";
+    rev = "v${version}";
+    sha256 = "05zbdkb9s6sfkni6k927795w2fqdhnf3i7kgl27715sdmmdab05d";
+  };
+
+  nativeBuildInputs = [ cmake ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp iDSK $out/bin
+  '';
+
+  meta = with lib; {
+    description = "Manipulating CPC dsk images and files";
+    homepage = "https://github.com/cpcsdk/idsk" ;
+    license = licenses.mit;
+    maintainers = [ ];
+    mainProgram = "iDSK";
+    platforms = platforms.all;
+  };
+}