nano /etc/phpmyadmin/config-db.php

$dbuser='usuário';
$dbpass='Senha';
$basepath='';
$dbname='bancodedados';
$dbserver='';
$dbport='';
$dbtype='mysql';

nano /etc/dbconfig-common/phpmyadmin.conf

# dbc_dbuser: database user
#       the name of the user who we will use to connect to the database.
dbc_dbuser='phpmyadmin'

# dbc_dbpass: database user password
#       the password to use with the above username when connecting
#       to a database, if one is required
dbc_dbpass='some_pass'