librem5: udev rules are incorrectly installed, resulting in broken PM and other things

Due to a packaging error on my part (from 67b5efce), udev rules aren't being installed correctly, and udev isn't loading any of them from the device package.

I have a patch to fix it, but holding off on submitting an MR since re-enabling modem PM causes the modem to enter a reset loop on my librem 5.