Intel PXA2xx CPUfreq driver

modulename: pxa2xx-cpufreq.ko

configname: CONFIG_ARM_PXA2xx_CPUFREQ

Linux Kernel Configuration
└─>Power management and ACPI options
└─>CPU Frequency scaling
└─>Intel PXA2xx CPUfreq driver
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This add the CPUFreq driver support for Intel PXA2xx SOCs.

If in doubt, say N.

source code:
drivers/cpufreq/pxa2xx-cpufreq.c