ref-manual: add WATCHDOG_TIMEOUT to variable glossary

In 4.1 the WATCHDOG_TIMEOUT variable is now used in two places, so let's
actually document it.

(From yocto-docs rev: c8e51a968a5942cd153dd4bcf82ba9d1cc5340c0)

Signed-off-by: Paul Eggleton <paul.eggleton@microsoft.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index ad9857082d..eaabdd2d4b 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -8872,6 +8872,10 @@ system and gives an overview of their function and contents.
       can control with this variable, see the
       ":ref:`ref-classes-insane`" section.
 
+   :term:`WATCHDOG_TIMEOUT`
+      Specifies the timeout in seconds used by the ``watchdog`` recipe and
+      also by ``systemd`` during reboot. The default is 60 seconds.
+
    :term:`WKS_FILE`
       Specifies the location of the Wic kickstart file that is used by the
       OpenEmbedded build system to create a partitioned image