widevine-cdm: fix eval outside unsupported platforms

{ stdenv, callPackage }:

{

  lib,

  stdenv,

  callPackage,

}:

callPackage (./. + "/${stdenv.hostPlatform.system}.nix") { inherit stdenv; }

let

  targets = lib.genAttrs [

    "aarch64-linux"

    "x86_64-linux"

  ] (name: ./. + "/${name}.nix");

in

callPackage (targets."${stdenv.hostPlatform.system}" or targets.x86_64-linux) { inherit stdenv; }