[BUGFIX] Fix wrong phpdoc for extbase plugin types

Resolves: #63535
Releases: master, 6.2
Change-Id: I406ca2534d4bf44c504cf31824ae161840274981
Reviewed-on: http://review.typo3.org/34960
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>