Remove redundant dependencies, accordingly to...

Remove redundant dependencies, accordingly to https://www.drupal.org/node/2120523#s-simple-configuration-vs-configuration-entities:

Simple configuration can only depend on the module that provides it. For example, system.site depends on the System module and nothing else.

As per my understanding, enforcing a dependency to the same module that defines that configuration is redundant. @luigisa could you please confirm if you added this for some reason? I remember we were trying to ensure dependencies were properly managed, but I think this can be safely removed.