Microsoft has just updated the following KB Article:
Reporting Services installation fails on System Center 2012 Configuration Manager Service Pack 1 that has SQL Server 2014 installed
Symptoms:
When you try to install the Reporting Services Point site system role in a System Center Configuration Manager Service Pack 1 (SP1) environment that was upgraded to Microsoft SQL Server 2014, the installation fails. Additionally, the Add Site System Roles Wizard indicates that it cannot reach the specified SQL Server instance.
Note The hotfix that is described in this article also applies to SQL Server 2014 SP1.
Full details at:
https://support.microsoft.com/en-us/kb/2923078