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

Built-in device tree for XLP EVP boards

configname: CONFIG_DT_XLP_EVP

Linux Kernel Configuration
└─>Built-in device tree for XLP EVP boards
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Add an FDT blob for XLP EVP boards into the kernel.
This DTB will be used if the firmware does not pass in a DTB
pointer to the kernel. The corresponding DTS file is at
arch/mips/netlogic/dts/xlp_evp.dts