The JBoss Hibernate ODA driver is placed in the org.jboss.tools.birt.oda plugin. If you want to use this driver, the plugin has to be in your WEB-INF/platform/plugins directory (JBoss Tools 3.2 and BIRT 2.6).
You also need to check if there are jboss-birt-servlet.jar and jboss-seam-birt.jar in the WEB-INF/lib directory
It is also necessary that your WEB-INF/platform/configuration/config.ini contains the following:
...
osgi.parentClassloader=fwk
org.osgi.framework.bootdelegation=org.hibernate,org.hibernate.type,org.hibernate.metadata,org.hibernate.ejb, javax.persistence
...
If you have created the project using the JBoss Tools wizard, the above mentioned requirements need to be satisfied.
If the plugin exists in the WEB-INF/lib directory, but you still have the problem, please open a jira on https://jira.jboss.org/jira/browse/JBIDE and provide the steps to reproduce the issue as well as the version of JBoss AS server and Seam runtime you are using.
BIRT 3.7.0 doesn't create the WEB-INF/platform directory. This change is causing the issue in JBT 3.3. I have opened https://issues.jboss.org/browse/JBIDE-9299 that is related to this issue.
Sorry for the inconvenience caused.