dt-bindings: mfd: da9063: watchdog: add suspend disable option

Document the watchdog disable option which can be used if the hardware
automatic suspend option is broken.

Based on commit c514430 ("dt-bindings: watchdog: da9062: add
suspend disable option").

Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Adam Thomson <DLG-Adam.Thomson.Opensource@dm.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220422072713.3172345-1-primoz.fiser@norik.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/devicetree/bindings/mfd/da9063.txt

@@ -64,10 +64,13 @@ Sub-nodes:
     and KEY_SLEEP.
 
 - watchdog : This node defines settings for the Watchdog timer associated
-  with the DA9063 and DA9063L. There are currently no entries in this
-  binding, however compatible = "dlg,da9063-watchdog" should be added
-  if a node is created.
+  with the DA9063 and DA9063L. The node should contain the compatible property
+  with the value "dlg,da9063-watchdog".
 
+  Optional watchdog properties:
+  - dlg,use-sw-pm: Add this property to disable the watchdog during suspend.
+  Only use this option if you can't use the watchdog automatic suspend
+  function during a suspend (see register CONTROL_B).
 
 Example: