dt-bindings: watchdog: Add fsl,scu-wdt yaml file

In order to replace the fsl,scu txt file from bindings/arm/freescale,
we need to split it between the right subsystems. This patch documents
separately the 'watchdog' child node of the SCU main node.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Viorel Suman <viorel.suman@nxp.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220707125022.1156498-9-viorel.suman@oss.nxp.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt

@@ -151,16 +151,6 @@ Optional Child nodes:
 - Data cells of ocotp:
   Detailed bindings are described in bindings/nvmem/nvmem.txt
 
-Watchdog bindings based on SCU Message Protocol
-------------------------------------------------------------
-
-Required properties:
-- compatible: should be:
-              "fsl,imx8qxp-sc-wdt"
-              followed by "fsl,imx-sc-wdt";
-Optional properties:
-- timeout-sec: contains the watchdog timeout in seconds.
-
 SCU key bindings based on SCU Message Protocol
 ------------------------------------------------------------
 
@@ -249,11 +239,6 @@ firmware {
 			linux,keycodes = <KEY_POWER>;
 		};
 
-		watchdog {
-			compatible = "fsl,imx8qxp-sc-wdt", "fsl,imx-sc-wdt";
-			timeout-sec = <60>;
-		};
-
 		tsens: thermal-sensor {
 			compatible = "fsl,imx8qxp-sc-thermal", "fsl,imx-sc-thermal";
 			#thermal-sensor-cells = <1>;