dt-bindings: watchdog: Add Qualcomm PM8916 watchdog

Document support for the Watchdog Timer (WDT) Controller in the
Qualcomm PM8916 PMIC module.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-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@linux-watchdog.org>

Documentation/devicetree/bindings/watchdog/qcom,pm8916-wdt.txt

+QCOM PM8916 watchdog timer controller
+
+This pm8916 watchdog timer controller must be under pm8916-pon node.
+
+Required properties:
+- compatible: should be "qcom,pm8916-wdt"
+
+Optional properties :
+- interrupts : Watchdog pre-timeout (bark) interrupt.
+- timeout-sec : Watchdog timeout value in seconds.
+
+Example:
+
+	pm8916_0: pm8916@0 {
+		compatible = "qcom,pm8916", "qcom,spmi-pmic";
+		reg = <0x0 SPMI_USID>;
+
+		pon@800 {
+			compatible = "qcom,pm8916-pon";
+			reg = <0x800>;
+
+			watchdog {
+				compatible = "qcom,pm8916-wdt";
+				interrupts = <0x0 0x8 6 IRQ_TYPE_EDGE_RISING>;
+				timeout-sec = <10>;
+			};
+		};
+	};