Comment # 2 on bug 1192047 from Micha������ Szczepaniak

Some additional info. You need to add start_x=1 (required
raspberry-firmware-extra), but you can't do it in extraconfig.txt it has to be
in config.txt(1). that added address 10 in i2c-detect which wasn't present
previously and imx219 (im using imx219 the v2 camera) uses that address, so
it's something. Still no /dev/video* though. Tried adding rest of parameters
like dtoverlay and gpu_mem in case maybe they need to be in config.txt too but
no luck.

1.
https://forums.raspberrypi.com/viewtopic.php?p=1860859&sid=77699a1b5a7b190259bb3b86544ba926#p1860859