CONFIG_ARM_LPAE is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Support for the Large Physical Address Extension

configname: CONFIG_ARM_LPAE

Linux Kernel Configuration
└─>Support for the Large Physical Address Extension
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Say Y if you have an ARMv7 processor supporting the LPAE page
table format and you would like to access memory beyond the
4GB limit. The resulting kernel image will not run on
processors without the LPA extension.

If unsure, say N.