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/rust/build-rust-crate/helpers.nix

@@ -0,0 +1,26 @@
+{stdenv, lib}:
+{
+  kernel = stdenv.hostPlatform.parsed.kernel.name;
+  abi = stdenv.hostPlatform.parsed.abi.name;
+  cpu = stdenv.hostPlatform.parsed.cpu.name;
+   updateFeatures = f: up: functions: lib.deepSeq f (lib.foldl' (features: fun: fun features) (lib.attrsets.recursiveUpdate f up) functions);
+   mapFeatures = features: map (fun: fun { features = features; });
+   mkFeatures = feat: lib.foldl (features: featureName:
+     if feat.${featureName} or false then
+       [ featureName ] ++ features
+     else
+       features
+   ) [] (lib.attrNames feat);
+  include = includedFiles: src: builtins.filterSource (path: type:
+     lib.any (f:
+       let p = toString (src + ("/" + f));
+       in
+       p == path || (lib.strings.hasPrefix (p + "/") path)
+     ) includedFiles
+  ) src;
+  exclude = excludedFiles: src: builtins.filterSource (path: type:
+    lib.all (f:
+       !lib.strings.hasPrefix (toString (src + ("/" + f))) path
+    ) excludedFiles
+  ) src;
+}