While there are documentation available on the SharePoint Farm upgrade which also included the DR farm (in my case hot stand by) for the SQL server log shipping mechanism, I could not find any reference or article on SharePoint patching on a SQL Server 2012 AlwaysOn setup with Asynchronous commit.
Although there is an article which says AlwaysOn Asynchronous replication is supported by SharePoint 2013, but in terms of SharePoint patching and what should be the approach nothing that I can find of.
If you are aware of any article, preferably Microsoft article or any blog post giving information on the above, please let me know.
Thanks in advance,
Sushanta
India SharePoint Group