CONFIG_BUILTIN_DTB is not available for thedefaultarchitecture x86.
Result is shown for architecture xtensa

DTB to build into the kernel image

configname: CONFIG_BUILTIN_DTB

Linux Kernel Configuration
└─>Platform options
└─>DTB to build into the kernel image
In linux kernel since version 3.1 (release Date: 2011-10-24)  
depends
CONFIG_OF