doc: example heading should be h2

The 'Example' heading should be on a lower level than 'bdinfo command'.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/usage/cmd/bdinfo.rst b/doc/usage/cmd/bdinfo.rst
index 6b3cde2..b287d0f 100644
--- a/doc/usage/cmd/bdinfo.rst
+++ b/doc/usage/cmd/bdinfo.rst
@@ -17,7 +17,7 @@
 The *bdinfo* command prints information about the board.
 
 Example
-=======
+-------
 
 ::