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

Change-Id: If6a4d52d203789086d0d884cf66c96155a124d56
Reviewed-on: http://review.typo3.org/35295
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>