CONFIG_ISA_ARCV2 is not available for thedefaultarchitecture x86.
Result is shown for architecture arc

ARC ISA v2

modulename: entry-arcv2.ko

configname: CONFIG_ISA_ARCV2

ARC Instruction Set
└─>ARC ISA v2
In linux kernel since version 3.10 (release Date: 2013-06-30)  
ISA for the Next Generation ARC-HS cores

source code: