Take a look in the MariaDB website's KnowledgeBase (I don't seem to be able to create any links here). According to this, you need to add something like this to your odbcinst.ini file:
[MariaDB ODBC 3.0 Driver]
Description = MariaDB Connector/ODBC v.3.0
Driver = /usr/lib64/libmaodbc.so
But the path would depend where you've installed the driver.