This was adapted from the Freshdesk plug for reversing the sort order for the customer portal.
<script type="text/javascript">
jQuery(document).ready(function(){
var con = document.getElementById('all_notes');
var els = Array.prototype.slice.call(con.childNodes);
for (var i = els.length -1; i>=0; i--) {
con.appendChild(els[i]);
}
})
</script>
</style>