default or selected kernelversion does not have config value CONFIG_PMC_ATOM.
Result is shown for kernelversion 6.9.9

CONFIG_PMC_ATOM (not configurable)

modulename: clk-pmc-atom.ko

and/or

pmc_atom.ko

configname: CONFIG_PMC_ATOM

Linux Kernel Configuration
└─>Device Drivers
└─>PCI support
└─>PMC_ATOM
In linux kernel since version 3.10 (release Date: 2013-06-30)  
source code:
drivers/clk/x86/clk-pmc-atom.c