CONFIG_PPC_P7_NAP is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

CONFIG_PPC_P7_NAP (not configurable)

modulename: idle_power7.ko

configname: CONFIG_PPC_P7_NAP

Linux Kernel Configuration
└─>Platform support
└─>PPC_P7_NAP
In linux kernel since version 3 (release Date: 2011-07-21)  
source code:
arch/powerpc/kernel/
is depended by
CONFIG_PPC_POWERNV