CONFIG_ARM64_ERRATUM_1188873 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result

configname: CONFIG_ARM64_ERRATUM_1188873

Linux Kernel Configuration
└─>Kernel Features
└─>ARM errata workarounds via the alternatives framework
└─>Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This option adds work arounds for ARM Cortex-A76 erratum 1188873

Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause
register corruption when accessing the timer registers from
AArch32 userspace.

If unsure, say Y.