That is incorrect.
SAP Solution Manager is a toolset that contains ASAP methodology, but Solution Manager is not the methodology. Probably someone confused about tool vs. content.
SAP still offers ASAP, but it has been succeeded by SAP Activate methodology that SAP introduced in 2015. See SAP.com/activate
While C_PM_71 certification exam is still listed on the SAP Education pages I would steer anyone to the SAP Activate exam that has been just released this week. While ASAP is still used in projects we are moving to SAP Activate and will gradually phase out ASAP content.
Best Regards, Jan