CONFIG_FSL_BOOKE is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc
default or selected kernelversion does not have config value CONFIG_FSL_BOOKE.
Result is shown for kernelversion 6.9.9

CONFIG_FSL_BOOKE (not configurable)

configname: CONFIG_FSL_BOOKE

Linux Kernel Configuration
└─>Processor support
└─>FSL_BOOKE
In linux kernel since version 2.6.15 (release Date: 2006-01-02)