ref-manual/variables.rst: WATCHDOG_TIMEOUT: fix recipe name

This variable affects the watchdog-config recipe, not the watchdog
recipe.

(From yocto-docs rev: d3350c38910c47c76ed17f24579120013589ca1f)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/variables.rst

@@ -10614,8 +10614,8 @@ system and gives an overview of their function and contents.
       ":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.
+      Specifies the timeout in seconds used by the ``watchdog-config`` recipe
+      and also by ``systemd`` during reboot. The default is 60 seconds.
 
    :term:`WIC_SECTOR_SIZE`
       The variable :term:`WIC_SECTOR_SIZE` controls the sector size of Wic