CONFIG_PM is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

Power Management support

modulename: pm.ko

and/or

kirkwood-pm.ko

and/or

mpc52xx_sleep.ko

and/or

lite5200_sleep.ko

and/or

sysfs.ko

and/or

main.ko

and/or

intel_epb.ko

configname: CONFIG_PM

Linux Kernel Configuration
└─>Power management options
└─>Power Management support
In linux kernel since version 2.6.12  
Support processor power management modes

source code:
/arch/arm/mach-sa1100/
depends
NOT CONFIG_MMU