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

Change-Id: I3193562777c638b78233473a6941c630bc6fbc72
Reviewed-on: http://review.typo3.org/35296
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>