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>

default.nix

@@ -0,0 +1,28 @@
+let requiredVersion = import ./lib/minver.nix; in
+
+if ! builtins ? nixVersion || builtins.compareVersions requiredVersion builtins.nixVersion == 1 then
+
+  abort ''
+
+    This version of Nixpkgs requires Nix >= ${requiredVersion}, please upgrade:
+
+    - If you are running NixOS, `nixos-rebuild' can be used to upgrade your system.
+
+    - Alternatively, with Nix > 2.0 `nix upgrade-nix' can be used to imperatively
+      upgrade Nix. You may use `nix-env --version' to check which version you have.
+
+    - If you installed Nix using the install script (https://nixos.org/nix/install),
+      it is safe to upgrade by running it again:
+
+          curl -L https://nixos.org/nix/install | sh
+
+    For more information, please see the NixOS release notes at
+    https://nixos.org/nixos/manual or locally at
+    ${toString ./nixos/doc/manual/release-notes}.
+
+    If you need further help, see https://nixos.org/nixos/support.html
+  ''
+
+else
+
+  import ./pkgs/top-level/impure.nix