mt6781-devs/android_kernel_xiaomi_mt6781 — reverse-engineered prompt

I have this Android Linux kernel source for Xiaomi MT6781 and I want you to make it easy to build and use. Please inspect the repo, figure out the right toolchain and config, fix obvious build errors, and add a simple script that cleans, builds, and puts the kernel image and device tree outputs in an out folder.

Also add a clear README for a beginner with prerequisites, commands, and where the finished files are. Keep the source changes minimal and don’t rewrite drivers unless needed. Target the lineage 23.2 branch and the MediaTek arm64 Android kernel setup that is already in the repo.

If anything depends on device specific blobs or a missing config, tell me clearly and leave a TODO instead of guessing. Look up current Android kernel build docs online if you need to.