This cuts downloads in half as only the needed sources are downloaded. It also makes the packages simpler and fixes a bug where the oneplus3t subpackage was overwriting the 20-adreno-gpu-firmware.files of the oneplus3 subpackage.
Combine firmware segments using pil-squasher, then install them in the paths specified in the device trees of oneplus3/3t.
After moving the firmware packages used by devices in community to device/community, move the rest of the firmware packages to device/testing.
