CONFIG_PPC_PSR2 is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

PowerEN System Reference Platform 2

modulename: psr2.ko

configname: CONFIG_PPC_PSR2

Linux Kernel Configuration
└─>WSP platform selection
└─>PowerEN System Reference Platform 2
In linux kernel since version 3 (release Date: 2011-07-21)  
source code:
arch/powerpc/platforms/wsp/psr2.c