Modify the site-title URL

add_filter( 'genesis_seo_title', 'child_header_title', 10, 3 );
/**
 * Modify the header URL.
 * @param  string $title  Existing title.
 * @param  string $inside Markup inside the title.
 * @param  string $wrap   The wrapping element (h1, h2, p, etc.) for the title.
 * 
 * @return string         Amended title.
 */
function child_header_title( $title, $inside, $wrap ) {

    $inside = sprintf( '<a href="http://example.com/" title="%s">%s</a>', esc_attr( get_bloginfo( 'name' ) ), get_bloginfo( 'name' ) );

    return sprintf( '<%1$s class="site-title">%2$s</%1$s>', $wrap, $inside );

}