I think so, I'll check here in a moment. The main reason for the post is simply to update the .dep file (assuming you're correct regarding inclusion) as the ext itself won't download otherwise.
/lib/modules/3.0.21-tinycore/kernel/drivers/cpufreq exists and isn't showing as also being in /tmp/tcloop/anywhere so yes, base it is. As such, I'm guessing it's safe to assume removal of cpufreq-KERNEL from .dep should be warranted. I'll try it on our repo...
The error's gone, but the ext crashes when trying to add it to the toolbar. (Mind you, I'm using Xvesa instead of Xorg so this may be involved since the extension was copied from TC3 and there's not much in the info file as to the expected foundation.)