Update Xilinx build documentation and remove unused scripts

[pamolloy]

No description provided.

[github-actions]

LLM review

This series clarifies the README (ADSP vs Xilinx sections), reverts legacy Travis/Azure CI
scripts that were superseded by GitHub Actions, and fixes trailing whitespace left by the first
commit. The commits themselves are clean, but the base commit db168fe (just below the range)
introduced a bug that prevents the hardware test from passing, and one commit in the series is
missing a sign-off.

run: 29258871673

---

db168fe - board/adi/ev-sc598-som: add post-image script to compress eMMC image

Dead-code bug: br2-external/board/adi/ev-sc598-som/post-image.sh is never executed.

The commit adds a post-image.sh to the br2-external tree whose only job is
gzip -f -k "${BINARIES_DIR}/emmc.img". The bootstrap installer
(board/adi/ev-sc598-som/bootstrap/overlay/init) downloads emmc.img.gz from the debug
build host over HTTP, so this file must exist in the debug-build artefact.

The base defconfig (buildroot/configs/adi_sc598_ezkit_defconfig) sets:

BR2_ROOTFS_POST_IMAGE_SCRIPT="board/adi/ev-sc598-som/post-image.sh support/scripts/genimage.sh"

Per the Buildroot manual, bare relative paths resolve to the Buildroot tree root, i.e.
buildroot/board/adi/ev-sc598-som/post-image.sh — which is the submodule's own script that
downloads u-boot.gdb via curl. The br2-external gzip script is never invoked.
configs/debug.fragment does not override BR2_ROOTFS_POST_IMAGE_SCRIPT either.

Result: emmc.img.gz is absent from the debug artefact → bootstrap hardware test fails
(hardware-test/hardware-test exit 1, .github line 369).

Fix — add to configs/debug.fragment:

BR2_ROOTFS_POST_IMAGE_SCRIPT="board/adi/ev-sc598-som/post-image.sh support/scripts/genimage.sh $(BR2_EXTERNAL_ADI_PATH)/board/adi/ev-sc598-som/post-image.sh"

This preserves the two existing steps (curl + genimage) and appends the gzip step after
emmc.img exists.

---

ed3dc12 - Revert "ci: add CI configuration and build scripts"

Missing Signed-off-by. All other commits in the series carry one; this revert does not.

---

CI warnings

The hardware-test/hardware-test failure is a direct consequence of the missing
configs/debug.fragment override described above, not an infrastructure issue.

Pre-existing check-package --br2-external warnings (hash column alignment, blank-line
ordering in .mk files, trailing whitespace in package/poll_sysfs/Config.in, etc.) are
present across multiple packages but were not introduced by this series.

---

Suggested patches

Apply the suggested patches with:

cd path/to/repository
export GITHUB_TOKEN=ghp_***
apply-patches --repo=analogdevicesinc/br2-external 29258871673

Install instructions

The following one-liner installs the script if not present already:

curl -fSsL "https://raw.githubusercontent.com/analogdevicesinc/doctools/refs/heads/main/ci/scripts/apply-patches.sh" \
     -o ~/.local/bin/apply-patches.sh && \
  grep -q "/apply-patches.sh" ~/.bashrc || echo "source ~/.local/bin/apply-patches.sh" >> $_ ; . $_

More information at AI Usage.