motorola-mt6878/hardware_motorola ? reverse-engineered prompt

Build out the hardware support code for a Motorola phone based on the MT6878 platform, so it can plug into Android cleanly.

I want this repo to contain the device side pieces needed for things like sensors, fingerprint under display, vendor interfaces, overlays, and the required security policy, so the phone can boot and work properly on Android. Please make sure the modules and configs are wired together in a sensible way, and add any missing glue code or build files needed for the hardware components to compile and fit into the system.

If anything depends on current Android source conventions or updated docs, look them up online and follow the latest approach. Keep it practical and focused on making the hardware layer usable on the device.