[CLEANUP] #5199 Use $GLOBALS['TCA'] instead of $TCA

Change-Id: Iccc9285573e3ab738e115d569375404ae17de538
Reviewed-on: http://review.typo3.org/35293
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>