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

CONFIG_ARCH_MULTI_CPU_AUTO (not configurable)

configname: CONFIG_ARCH_MULTI_CPU_AUTO

Linux Kernel Configuration
└─>System Type
└─>Multiple platform selection
└─>ARCH_MULTI_CPU_AUTO
In linux kernel since version 3.1 (release Date: 2011-10-24)