The most recent (well, this is the mostest recent) update of ACPICA for DragonFly, by Sascha Wildner, is different from the usual import: it happens to include actual upstream support for DragonFly
A running description of activity related to DragonFly BSD.
The first upstream commit mentioned (chronologically it is the second), https://github.com/acpica/acpica/commit/3e93431674abe947202b0f9a0afa7b625b17caa6, isn’t part of the most recent release, though. It didn’t make it in in time but will be part of the next release (in a month or two, I assume).