Believe me, I'm fully aware of the differences between copyright and patents. But the "open source" licensing isn't so different between the two.
Open source licensing originated with copyright because, in the US, it is not possible to release something into the public domain. Your copyright is automatic and you can't renounce it.
OSS licenses are an attempt to leverage copyright law in order to accomplish something that approximates the important features of putting something in the public domain.
This is not necessary with patents, because nothing is automatically patented and you can absolutely renounce patents.
That said, as OSS licenses evolved, they became more than trying to approximate putting things in the public domain. They started to carve out a space that isn't fully public domain, but also isn't fully proprietary.
It's this sort of licensing that could have huge value with hardware. And that licensing would rest on the legal rights of having a patent, just like how with software, it rests on the legal rights of having copyright.
So, in the end, the principle is the same regardless of whether the underpinnings is copyright or patent.
Although, since (unlike copyright), patents actually have a reasonably short lifespan, this effort is less necessary with hardware. It's entirely feasible just to wait until the patents expire and they enter the public domain.