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/src-only/default.nix

@@ -0,0 +1,31 @@
+{ stdenv }@orig:
+# srcOnly is a utility builder that only fetches and unpacks the given `src`,
+# maybe pathings it in the process with the optional `patches` and
+# `buildInputs` attributes.
+#
+# It can be invoked directly, or be used to wrap an existing derivation. Eg:
+#
+# > srcOnly pkgs.hello
+#
+{ name
+, src
+, stdenv ? orig.stdenv
+, patches ? []
+, # deprecated, use the nativeBuildInputs
+  buildInputs ? []
+, # used to pass extra unpackers
+  nativeBuildInputs ? []
+, # needed when passing an existing derivation
+  ...
+}:
+stdenv.mkDerivation {
+  inherit
+    buildInputs
+    name
+    nativeBuildInputs
+    patches
+    src
+    ;
+  installPhase = "cp -r . $out";
+  phases = ["unpackPhase" "patchPhase" "installPhase"];
+}