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

Netlogic XLP based systems

configname: CONFIG_NLM_XLP_BOARD

System type
└─>Netlogic XLP based systems
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This board is based on Netlogic XLP Processor.
Say Y here if you have a XLP based board.