d2: Add asserts for our devices

Signed-off-by: Brandon McAnsh <brandon.mcansh@gmail.com>
d2: TARGET_UNIFIED_DEVICE

Signed-off-by: Brandon McAnsh <brandon.mcansh@gmail.com>
init_d2: use strstr to match bootloader

* And set rild.libargs once

Signed-off-by: Brandon McAnsh <brandon.mcansh@gmail.com>