There is a new pull request by thypon against master on the void-packages repository

https://github.com/thypon/void-packages overclock-pinebook
https://github.com/void-linux/void-packages/pull/28007

pinebookpro-kernel: overclock patch
Pinebook PRO uses the same OP1 RK3399 of many other chromebooks devices. 
These devices has been rated for 2.1Ghz max clock speed.
Use the OP1 profile already present in the kernel tree.

@ericonr @CameronNemo 

A patch file from https://github.com/void-linux/void-packages/pull/28007.patch is attached