"modprobe speedstep_smi" in bootlocal.sh is what I have thus far, and all that is needed to make scaling work.
Interestingly enough, speedstep_lib which appears to be a dependency of speedstep_smi does get autoloaded.
Point in case is that with my setup the cpu will only run at full frequency after speedstep_smi has been loaded, which currently with bootlocal.sh is at a very late point in the boot process.
Therefore with the goal to speed up the boot process I would like to have the module loaded as early as possible and wondered if that could perhaps be done with a somewhat reverse way of blacklisting, by explicitely specifying a module to be loaded.