Split i9300 into separate packages and use codenames, and set up WiFi properly on mainline

m0 and m3 are the "real" codenames for i9300 and i9305, respectively. Furthermore, it doesn't make much sense to keep these two in the same device package (I can only maintain m0 since I don't own an m3), and even less the downstream kernel since the gpu_accelerated property is shared between mainline and downstream but should have a different value for downstream than mainline.

Anyway, as mentioned, I don't have an m3! If you have one, testing is very welcome. I haven't tested this on my m0 yet, thus it's a draft.

Added to renamed devices: https://wiki.postmarketos.org/wiki/Renamed_Devices

Part-of https://gitlab.com/postmarketOS/pmaports/-/issues/35
Closes https://gitlab.com/postmarketOS/pmaports/-/issues/1017