Now the packages mariadb-common, mariadb-client and mariadb-server each
install their own cnf file. A system will not have extra cnf files around.

Also the .cnf files list all possible stanzas that can be used to
compartmentalize settings for different binaries.

Role model was upstream
https://github.com/MariaDB/server/tree/83ba48b7c670f6dba465325cafd808c91f551544/support-files/rpm