port use: MARIADB_USES= mysql:104m which doens't take into account preference defined in /etc/make.conf, for exmaple: DEFAULT_VERSIONS+= mysql=10.5m so it will not be possible to install kodi if another mariadb version is selected as default
MARIADB is mainly for package. If DEFAULT_VERSIONS is set, you should select MYSQL. Let me know if that solves the problem. Sorry for delay.