ARM: dts: imx7d-sdb: Use WDOG_B pin reset

imx7d-sdb has WDOG1_B pin connected to the PMIC.

Pass the 'fsl,ext-reset-output' property so that the watchdog
can trigger a system POR reset via the PMIC.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx7d-sdb.dts

@@ -314,6 +314,12 @@ &usdhc3 {
 	status = "okay";
 };
 
+&wdog1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_wdog>;
+	fsl,ext-reset-output;
+};
+
 &iomuxc {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_hog>;
@@ -512,5 +518,10 @@ MX7D_PAD_SD3_STROBE__SD3_STROBE		0x1b
 			>;
 		};
 
+		pinctrl_wdog: wdoggrp {
+			fsl,pins = <
+				MX7D_PAD_GPIO1_IO00__WDOD1_WDOG_B	0x74
+			>;
+		};
 	};
 };