CONFIG_EVA is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_EVA (not configurable)

configname: CONFIG_EVA

Linux Kernel Configuration
└─>EVA
In linux kernel since version 3.15 (release Date: 2014-06-08)  
is selected by
CONFIG_CPU_MIPS32_R5_XPA

is depended by
CONFIG_CPU_MIPS32_3_5_EVA