The Smarts SAM Adapters 8.1.3 Patch 2 Readme documents this as follows:
SAM Adapter and OS configuration Support for SCOM 2012 is included in this version along with SCOM 2007 ( ONLY on Windows Server 2008 R2 SP1 )
NOTE: The base 8.1.3 installation of SCOM 2007 Adapter is required in order to add support for SCOM 2012. Ensure that you have selected the "Adapter for Microsoft System Center Operations Manger 2007 R2" feature during SAM Adapters Suite 8.1.3 installation. To add support for SCOM 2012, install Patch 2 for SAM Adapters 8.1.3.