....scaling_available_frequencies //available frequencies
....scaling_available_governors //available governors
2997000 2664000 2331000 1998000
If Linux kernel cpufreq comes from the Device Tree table. You have to modify your device tree.
But if the Linux kernel cpufreq comes from the firmware ( for example, Arm Juno board), you have to modify the firmware e.g. Arm Trusted Firmware or System Control Processor firmware or the corresponding firmware in your system.
The chart comes from Arm SCMI procotol.
Based on above, you have to figure out what is your target board and what is OS/firmware running on that. Then modify them accordingly.