Add firmware required to make WiFi work. Patch the kernel so the ramoops
dmesgs can be read properly without having to remove that header every
time.
[skip ci]: already built successfully in CI
Initial support for Xiaomi A1 aka xiaomi-tissot using LineageOS 15.1
kernel, has similar board to Xiaomi Redmi 4 aka xiaomi-mido with some
differences that had to be patched such as reversing skip_initramfs and
ignoring dm param. 16.0 kernel boots but display fb init doesn't work.
Weston boots with touch support, SSH via USB RNDIS works.
[skip ci]: this built once in CI already, good to go.