CONFIG_ARCH_VEXPRESS_TC2_PM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Versatile Express TC2 power management

modulename: tc2_pm.ko

configname: CONFIG_ARCH_VEXPRESS_TC2_PM

Linux Kernel Configuration
└─>Versatile Express platform type
└─>Versatile Express TC2 power management
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Support for CPU and cluster power management on Versatile Express
with a TC2 (A15x2 A7x3) big.LITTLE core tile.

source code:
arch/arm/mach-vexpress/tc2_pm.c