pinebookpro: Fix build failing

[ryonakano]

This PR fixes building the image for Pinebook Pro failing (see https://github.com/elementary/os/pull/731#issuecomment-2453619649).

Changes Summary

• Fix dead link to TF-A tarball
  • Tagged tarballs available on official Gitiles seems to be generated on every download, which means timestamp differs on every download and can't use sha256sum to validate. This is the reason why I replaced to the link on GitHub mirror.
• Add patches to TF-A to fix build error on OS 8 RC
• Update Linux kernel config because there seems to be new options and I was asked when the build script runs make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- oldconfig
• Use artifacts dir which is in the .gitignore

[ryonakano]

I built this branch natively on my OS 8 RC and confirmed this generates a Pinebook Pro image. However, I can't test if the generated image works as expected because I don't have a Pinebook Pro.

@davidmhewitt @stsdc Do you have a PineBook Pro? If so, would you build this branch and check if the generated image is bootable on it?

[ryonakano]

Hmm, looks like build native generates an image successfully but build on Docker fails with the following error:

du: cannot access '/working_dir/artifacts/pinebook-pro/elementary-arm64/proc/336229/task/336229/fd/3': No such file or directory
du: cannot access '/working_dir/artifacts/pinebook-pro/elementary-arm64/proc/336229/task/336229/fdinfo/3': No such file or directory
du: cannot access '/working_dir/artifacts/pinebook-pro/elementary-arm64/proc/336229/fd/4': No such file or directory
du: cannot access '/working_dir/artifacts/pinebook-pro/elementary-arm64/proc/336229/fdinfo/4': No such file or directory
Creating image file
Warning: The resulting partition is not properly aligned for best performance: 62500s % 2048s != 0s
losetup: /working_dir/artifacts/pinebook-pro/elementaryos-6.1-daily-pinebookpro-20241104.img: failed to set up loop device: No such file or directory
[ryo@b760m ~/work/elementary/os (ryonakano/pinebookpro-fix-build)]$

[ryonakano]

OK, retrying the docker build generates the image succesfuly.