CONFIG_PM is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
Power Management support (EXPERIMENTAL)
modulename: pm.ko
and/orstandby.ko
and/ormain.ko
and/orcpu.ko
and/orsuspend.ko
configname: CONFIG_PM
Linux/MIPS Kernel Configuration
└─>Executable file formats
└─>Power Management support (EXPERIMENTAL)