watchdog: renesas-wdt: add support for rza

Describe the WDT hardware in the RZ/A series.
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Documentation/devicetree/bindings/watchdog/renesas-wdt.txt

@@ -2,10 +2,11 @@ Renesas Watchdog Timer (WDT) Controller
 
 Required properties:
 - compatible : Should be "renesas,<soctype>-wdt", and
-	       "renesas,rcar-gen3-wdt" as fallback.
+	       "renesas,rcar-gen3-wdt" or "renesas,rza-wdt" as fallback.
 	       Examples with soctypes are:
 	         - "renesas,r8a7795-wdt" (R-Car H3)
 	         - "renesas,r8a7796-wdt" (R-Car M3-W)
+	         - "renesas,r7s72100-wdt" (RZ/A1)
 
   When compatible with the generic version, nodes must list the SoC-specific
   version corresponding to the platform first, followed by the generic
@@ -17,6 +18,7 @@ Required properties:
 Optional properties:
 - timeout-sec : Contains the watchdog timeout in seconds
 - power-domains : the power domain the WDT belongs to
+- interrupts: Some WDTs have an interrupt when used in interval timer mode
 
 Examples: