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>

nixos/doc/manual/from_md/development/importing-modules.section.xml

@@ -0,0 +1,47 @@
+<section xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="sec-importing-modules">
+  <title>Importing Modules</title>
+  <para>
+    Sometimes NixOS modules need to be used in configuration but exist
+    outside of Nixpkgs. These modules can be imported:
+  </para>
+  <programlisting language="bash">
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [ # Use a locally-available module definition in
+      # ./example-module/default.nix
+        ./example-module
+    ];
+
+  services.exampleModule.enable = true;
+}
+</programlisting>
+  <para>
+    The environment variable <literal>NIXOS_EXTRA_MODULE_PATH</literal>
+    is an absolute path to a NixOS module that is included alongside the
+    Nixpkgs NixOS modules. Like any NixOS module, this module can import
+    additional modules:
+  </para>
+  <programlisting language="bash">
+# ./module-list/default.nix
+[
+  ./example-module1
+  ./example-module2
+]
+</programlisting>
+  <programlisting language="bash">
+# ./extra-module/default.nix
+{ imports = import ./module-list.nix; }
+</programlisting>
+  <programlisting language="bash">
+# NIXOS_EXTRA_MODULE_PATH=/absolute/path/to/extra-module
+{ config, lib, pkgs, ... }:
+
+{
+  # No `imports` needed
+
+  services.exampleModule1.enable = true;
+}
+</programlisting>
+</section>