Add 'deprecated' docblock to 'defer' property

Author: svenluijten

src/Illuminate/Support/ServiceProvider.php

@@ -17,6 +17,8 @@ abstract class ServiceProvider
     /**
      * Indicates if loading of the provider is deferred.
      *
+     * @deprecated 5.8 Implement the \Illuminate\Contracts\Support\Deferred interface instead.
+     *
      * @var bool
      */
     protected $defer = false;