Display Custom Post Type in divs just thumb and title

erase all the code above from your functions.php and use this:

function cw_post_type_portfolio() {

  $supports = array(
    'title', // post title
    'editor', // post content
    'author', // post author
    'thumbnail', // featured images
    'excerpt', // post excerpt
    'custom-fields', // custom fields
    'comments', // post comments
    'revisions', // post revisions
    'post-formats', // post formats
  );

  $labels = array(
    'name' => _x('portfolios', 'plural'),
    'singular_name' => _x('portfolio', 'singular'),
    'menu_name' => _x('portfolio', 'admin menu'),
    'name_admin_bar' => _x('portfolio', 'admin bar'),
    'add_new' => _x('Add New', 'add new'),
    'add_new_item' => __('Add New portfolio'),
    'new_item' => __('New portfolio'),
    'edit_item' => __('Edit portfolio'),
    'view_item' => __('View portfolio'),
    'all_items' => __('All portfolios'),
    'search_items' => __('Search portfolios'),
    'not_found' => __('No portfolios found.'),
  );

  $args = array(
    'supports' => $supports,
    'labels' => $labels,
    'public' => true,
    'query_var' => true,
    'rewrite' => array('slug' => 'portfolio'),
    'has_archive' => true,
    'hierarchical' => false,
  );
  register_post_type('mla_portfolio', $args);
}
add_action('init', 'cw_post_type_portfolio');

/*Custom Post type end*/

I’ve edited a few lines including removing duplication issues and using the actual $supports array which wasn’t included in the function call. I’ve also changed your posttype from plain portfolio to mla_portfolio so you’ll need to change the code for your wp_query to the correct reference.

The reason your h4 isn’t working is because you used the_title() instead of get_the_title().

UPDATE

added query code:

<section>
    <div class="portfolio">
        <div class="row">
        <?php
            $args = array( 'post_type' => 'mla_portfolio', 'posts_per_page' => 10 );
            $loop = new WP_Query( $args );
            while ( $loop->have_posts() ) : $loop->the_post();
                echo '<div class="col-md-4">';
                  echo '<h4>'.get_the_title().'</h4>';
                  echo '<a href="' . get_permalink() . '">' . get_the_post_thumbnail() . '</a>';
                echo '</div>';
            endwhile;
        ?>
        </div>
    </div>
</section>