По идее сделать так:
<div id="content" >
<h1><?php echo $heading_title; ?></h1>
<?php if ($categories) { ?>
<div class="manufaklist">
<?php foreach ($categories as $category) { ?>
<?php foreach (array_chunk($category['manufacturer'], 4) as $manufacturers) { ?>
<?php foreach ($manufacturers as $manufacturer) { ?>
<div class="item">
<a href="<?php echo $manufacturer['href']; ?>"><?php echo $manufacturer['name']; ?></a>
</div>
<?php } ?>
<?php } ?>
<?php } ?>
</div>
<?php } else { ?>
</div>