I looked briefly in kernel code and it looks like:

if you have vdd2_opp > 2 it means you have some application which grabs some ARM resource - DSP, SGX, audio etc. VDD2 is automatically set by calculation of overall bandwidth of internal CPU bus - it boosts voltage if there is some transfer via internal bus to special ARM CPU resource.

You have VDD2 == 3 even with 125MHz and that is probably some energy leak on low frequencies.