Binary blob came from linaro:
- https://releases.linaro.org/96boards/rb5/linaro/rescue/21.12

Source code is from:
- aosp: https://git.codelinaro.org/linaro/qcomlt/abl/-/commits/release/LU.UM.1.2.1.r1-23200-QRB5165.0-v4-header
- linux: https://git.codelinaro.org/linaro/qcomlt/abl/-/commits/release/LU.UM.1.2.1.r1-23200-QRB5165.0

But it needs closed-source signing tool [1][2] from qcom to sign
the binary, so we have to treat it as firmware file.

[1] https://git.linaro.org/ci/job/configs.git/tree/lt-qcom-bootloader/rb5/builders.sh#n126
[2] https://discuss.96boards.org/t/how-to-get-and-customize-the-bootloader/11128
