use the interconnect framework to set frequencies in devfreq
The target branch here might not make sense: It's the few commits above the merge-commits in the tree.
This implements our devfreq needs onto the most recent solution for the mainline tree.
Important: This depends on librem5-devkit-tools!145 (merged) being at users before! So at least a new
Breaks relation to l5-devkit-tools (+a release) is needed.