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

Netlogic XLR SoC

modulename: c-r4k.ko

and/or

dump_tlb.ko

and/or

r4k_fpu.ko

configname: CONFIG_CPU_XLR

CPU type
└─>Netlogic XLR SoC
In linux kernel since version 3 (release Date: 2011-07-21)  
Netlogic Microsystems XLR/XLS processors.

source code:
arch/mips/mm/


is selected by
CONFIG_NETLOGIC_XLR_NET