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/dhall-modules/lib.nix

@@ -0,0 +1,25 @@
+{ lib }:
+
+let
+  # This is essentially the same thing as `lib.makeOverridable`, except storing
+  # the override method in a method named `overridePackage` so that it's not
+  # shadowed by the `override` method added by `callPackage`
+  makePackageOverridable = f: args:
+    let
+      result = lib.makeOverridable f args;
+
+      copyArgs = g: lib.setFunctionArgs g (lib.functionArgs f);
+
+      overrideWith =
+        update: args // (if lib.isFunction update then update args else update);
+
+      overridePackage =
+        copyArgs (update: makePackageOverridable f (overrideWith update));
+
+    in
+      result // { inherit overridePackage; };
+
+in
+  lib // {
+    inherit makePackageOverridable;
+  }