SET @sql = NULL ;
SELECT GROUP_CONCAT( DISTINCT CONCAT( 'sum(CASE WHEN fecha = ''', fecha, ''' THEN asistencia else '''' END) AS `', fecha, '`' ) )
INTO @sql
FROM asistencia;
iSET @sql = CONCAT( 'SELECT s.dui, nombres,apellidos, codigo,nombre,depto,muni,', @sql , '
        from docentes1 c
        inner join asistencia s
          on c.dui = s.dui
       INNER JOIN centros e
       ON c.centro = e.codigo
       AND c.sede=11117
       AND s.asistencia=1
       group by s.dui' );
PREPARE stmt FROM @sql;
EXECUTE stmt;

$stmt = $dbh->prepare("CALL mystore(:dato)");
$stmt -> bindParam(':dato',$dato);

// call the stored procedure
$stmt->execute();

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "formacion";


    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    // set the PDO error mode to exception
    //$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // prepare sql and bind parameters
    $stmt = $conn->query("SELECT . . . ");

SET @sql = NULL;

SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'sum(CASE WHEN fecha = ''',
      fecha,
      ''' THEN asistencia else '''' END) AS `',
      fecha, '`'
    )
  ) INTO @sql
FROM asistencias_nueva1;


SET @sql
 = CONCAT('SELECT s.dui, nombres,apellidos, codigo,nombre,depto,muni,', @sql, '
            from docentes1 c
            inner join asistencias_nueva1 s
              on c.dui = s.dui
           INNER JOIN centros e
           ON c.centro = e.codigo
           AND c.sede052017u2=12347
          AND s.unidad=2
           group by s.dui');


PREPARE stmt FROM @sql;

EXECUTE stmt;