docs: xtensa: convert to ReST

Rename the xtensa documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/xtensa/index.rst b/Documentation/xtensa/index.rst
new file mode 100644
index 000000000000..5a24e365e35f
--- /dev/null
+++ b/Documentation/xtensa/index.rst
@@ -0,0 +1,12 @@
+:orphan:
+
+===================
+Xtensa Architecture
+===================
+
+.. toctree::
+   :maxdepth: 1
+
+   atomctl
+   booting
+   mmu