CONFIG_ARMV8_DEPRECATED is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Emulate deprecated/obsolete ARMv8 instructions

modulename: armv8_deprecated.ko

configname: CONFIG_ARMV8_DEPRECATED

Linux Kernel Configuration
└─>Kernel Features
└─>Kernel support for 32-bit EL0
└─>Emulate deprecated/obsolete ARMv8 instructions
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Legacy software support may require certain instructions
that have been deprecated or obsoleted in the architecture.

Enable this config to enable selective emulation of these
features.

If unsure, say Y

source code:
depends
CONFIG_COMPAT
CONFIG_SYSCTL