JBoss Tools takes into account only resources in folder %web root folder%/resources, and it can only find the web root folder if the project is a Dynamic Web Project. JBoss Tools have no way to determine which other folders contribute to resources of deployed project. If your project is not a Dynamic Web Project, please run action 'Configure -> Add JSF Capabilities'.
If it does not help, for instance because validator still does not see resources from other folders and you would not move all resources under web root folder, then just disable 'JSF2 Components Validator' in Preferences -> Validation (or in properties of a specific project).