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

CONFIG_SYS_HAS_CPU_XLP (not configurable)

configname: CONFIG_SYS_HAS_CPU_XLP

Linux Kernel Configuration
└─>CPU selection
└─>SYS_HAS_CPU_XLP
In linux kernel since version 3.1 (release Date: 2011-10-24)  
is selected by
CONFIG_CPU_XLP