Add Featured Image Support to All Post Types

<?php
add_action( 'init', 'scseed_thumbnails_all_cpts', 20 );
if ( ! function_exists( 'scseed_thumbnails_all_cpts' ) ) {
    function scseed_thumbnails_all_cpts() {
        $post_types = get_post_types( array( 'public' => true ), 'names' );
        foreach ( $post_types as $post_type ) {
            if ( ! post_type_supports( $post_type, 'thumbnail' ) ) {
                add_post_type_support( $post_type, 'thumbnail' );
            }
        }
    }
}