[PATCH v2 1/7] doc: make pdfdocs: Specify texlive-xetex as a prerequisite

[Adriano Carvalho]

Dockerfile updated as well.

If I don't apt install texlive-xetex, this is what I get with
docker.io/trini/u-boot-gitlab-ci-runner:jammy-20250714-25Jul2025:

uboot at 35c89b9ab70e:~/u-boot$ make pdfdocs
  HOSTCC  scripts/basic/fixdep
doc/Makefile:89: The 'xelatex' command was not found. Make sure you have it installed and in PATH to produce PDF output.
  SKIP    Sphinx pdfdocs target.

NOTE: This won't completely fix the pdfdocs target. See next commit(s).

Signed-off-by: Adriano Carvalho <adrianocarvalho.pt at gmail.com>
---
 doc/build/documentation.rst | 2 ++
 tools/docker/Dockerfile     | 1 +
 2 files changed, 3 insertions(+)

diff --git a/doc/build/documentation.rst b/doc/build/documentation.rst
index b55a4666643..81548390d78 100644
--- a/doc/build/documentation.rst
+++ b/doc/build/documentation.rst
@@ -16,6 +16,8 @@ the following dependencies are needed to build the documentation:
 
 * texinfo (if building the `Infodoc documentation`_)
 
+* texlive-xetex (if building the `PDF documentation`_ through the *pdfdocs* target)
+
 When submitting patches for documentation always build with KDOC_WERROR=1 to
 treat warnings as errors.
 
diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
index 5b4c75f8400..8e166eda4bc 100644
--- a/tools/docker/Dockerfile
+++ b/tools/docker/Dockerfile
@@ -136,6 +136,7 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
 	sudo \
 	swig \
 	texinfo \
+	texlive-xetex \
 	util-linux \
 	uuid-dev \
 	vboot-kernel-utils \
-- 
2.34.1