CONFIG_PPC_BOOK3S_64 is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

CONFIG_PPC_BOOK3S_64 (not configurable)

modulename: cpu_setup_power7.ko

and/or

cpu_setup_ppc970.ko

configname: CONFIG_PPC_BOOK3S_64

Linux Kernel Configuration
└─>Processor support
└─>PPC_BOOK3S_64
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  

depends
CONFIG_PPC64

is selected by
CONFIG_KVM_BOOK3S_64