I think that that would be the 'Dragonlance Campaign Setting', I will double check this when I get home and get in my garage box (none of my groups wish to allow or even consider any of the DL material for our game). [EDIT: I added my reasoning based on the mentioned book at the bottom of this post]
Cover shot of the book:
I dug up my old book and the only mention of Kender and religion is as follows:
Though kender recognize all the deities (to avoid hurting any of god's
feelings), they hold Branchala, Chislev, Mishakal, and Gilean in
highest regard. Reorx is viewed as a grumbling but benevolent
grandfather, but kender do not specifically praise him.
The book further mentions that the because of Tasslehof, some kender also regard Fizban (One of Paladine's avatars) as a revered deity.
I personally am tempted to go with Branchala as the primary deity because the description of him fits the most with my idea of kender, the deities description begins as follows for instance:
The Bard King, Branchala, brings joy to the people of the world
through melody and merriment with his unending sonf of life.
The idea of a god who's main goal is to make people happy seems to fit really well with the general wanderlust/careless nature of the Kender.