This page contains a link to the XML reference guides and XML schema documents for Xml Configuration with Camel releases. You can refer to http://camel.apache.org/schema/ to see the individual XSDs available.
Your IDE won't be able to fetch this XSD, you'll have to manually associate a specific release; however it does mean that you won't have to upgrade your XML config file with each Camel release; as it will resolve this XSD using the bundled XSD inside the camel-spring.jar.