[BUGFIX] Adapt TCA signature for customControls to the documentation

According to the documentation since TYPO3 v4.7, the definition of
"customControls" for "inline" columns should be a numerical array
with at least a "userFunc" key, just as any user function.

Releases: master, 8.7
Resolves: #83750
Change-Id: I2617cc9af9d642715b908296a2d75a3945b86cbb
Reviewed-on: https://review.typo3.org/57525


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Jörg Bösche <typo3@joergboesche.de>
Reviewed-by: Łukasz Uznański <l.uznanski@macopedia.pl>
Tested-by: Łukasz Uznański <l.uznanski@macopedia.pl>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>