CONFIG_CPU_MIPS32_3_5_EVA is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Enhanced Virtual Addressing (EVA)

configname: CONFIG_CPU_MIPS32_3_5_EVA

Linux Kernel Configuration
└─>CPU selection
└─>Enhanced Virtual Addressing (EVA)
In linux kernel since version 3.15 (release Date: 2014-06-08)  
Choose this option if you want to enable the Enhanced Virtual
Addressing (EVA) on your MIPS32 core (such as proAptiv).
One of its primary benefits is an increase in the maximum size
of lowmem (up to 3GB). If unsure, say 'N' here.