<div class="col-md-4 mb-4 md-form">
                    <label for="tipopqr">Tipo PQR</label>
                    <select class="form-control" name="tipopqr" id="lista1" onkeypress="return tabular(event,this)" required>
                        <option value="">Seleccione</option>
                        <?php while ($filat = mysqli_fetch_array($tipopqr)) : ?>
                            <option value="<?= $filat['pqr_tip_id']; ?>"> <?= utf8_encode($filat['pqr_tip_nom']); ?></option>
                        <?php endwhile ?>
                    </select>
                </div>

<div class="col-md-4 mb-4 md-form" id="select2lista">


<script type="text/javascript">
    $(document).ready(function(){
        recargarLista();

        $('#lista1').change(function(){
            recargarLista();
        });
    })
</script>
<script type="text/javascript">
    function recargarLista(){
        $.ajax({
            type:"POST",
            url:"funcionespqr/select_subtipo.php",
            data:"tipo=" + $('#lista1').val(),
            success:function(r){
                $('#select2lista').html(r);
            }
        });
    }
</script>