"MariaDB is one of the most popular database servers in the world. It’s made by the original developers of MySQL and guaranteed to stay open source. Notable users include Wikipedia, Facebook and Google." Source: https://mariadb.org/about/
MariaDB is supported by GeneXus, since it is a MySQL. So any configuration in GeneXus is the same as MySQL and all GeneXus / MySQL considerations apply.
"For all practical purposes, MariaDB is a binary drop in replacement of the same MySQL version (for example MySQL 5.1 -> MariaDB 5.1, MariaDB 5.2 & MariaDB 5.3 are compatible. MySQL 5.5 is compatible with MariaDB 5.5 and also in practice with MariaDB 10.0)." Source: https://mariadb.com/kb/en/mariadb/mariadb-vs-mysql-compatibility/
So you may use the same drivers than the ones for MySQL. Recommended reading: https://mariadb.com/kb/en/mariadb/mariadb-vs-mysql-compatibility/