docs: aoe: add it to the driver-api book

Those files belong to the admin guide, so add them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Justin Sanders <justin@coraid.com>
diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst
index 9228fbf..1f0d9b9 100644
--- a/Documentation/admin-guide/index.rst
+++ b/Documentation/admin-guide/index.rst
@@ -83,6 +83,7 @@
    namespaces/index
    perf-security
    acpi/index
+   aoe/index
    device-mapper/index
    laptops/index