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/build-support/fetchipfs/default.nix

@@ -0,0 +1,50 @@
+{ stdenv
+, curl
+}:
+
+{ ipfs
+, url            ? ""
+, curlOpts       ? ""
+, outputHash     ? ""
+, outputHashAlgo ? ""
+, md5            ? ""
+, sha1           ? ""
+, sha256         ? ""
+, sha512         ? ""
+, meta           ? {}
+, port           ? "8080"
+, postFetch      ? ""
+, preferLocalBuild ? true
+}:
+
+let
+
+  hasHash = (outputHash != "" && outputHashAlgo != "")
+    || md5 != "" || sha1 != "" || sha256 != "" || sha512 != "";
+
+in
+
+if (!hasHash) then throw "Specify sha for fetchipfs fixed-output derivation" else stdenv.mkDerivation {
+  name = ipfs;
+  builder = ./builder.sh;
+  nativeBuildInputs = [ curl ];
+
+  # New-style output content requirements.
+  outputHashAlgo = if outputHashAlgo != "" then outputHashAlgo else
+      if sha512 != "" then "sha512" else if sha256 != "" then "sha256" else if sha1 != "" then "sha1" else "md5";
+  outputHash = if outputHash != "" then outputHash else
+      if sha512 != "" then sha512 else if sha256 != "" then sha256 else if sha1 != "" then sha1 else md5;
+
+  outputHashMode = "recursive";
+
+  inherit curlOpts
+          postFetch
+          ipfs
+          url
+          port
+          meta;
+
+  # Doing the download on a remote machine just duplicates network
+  # traffic, so don't do that.
+  inherit preferLocalBuild;
+}