ARM: dts: imx6dl-colibri: Command pmic to standby for poweroff

The Colibri iMX6 HW doesn't allow to use the PWR_ON_REQ signal for
poweroff. Use the fsl,pmic-stby-poweroff property to command the PMIC
into a low power mode in poweroff.
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-colibri.dtsi

@@ -138,6 +138,10 @@ &can2 {
 	status = "disabled";
 };
 
+&clks {
+	fsl,pmic-stby-poweroff;
+};
+
 /* Colibri SSP */
 &ecspi4 {
 	cs-gpios = <&gpio5 2 GPIO_ACTIVE_LOW>;
@@ -403,6 +407,7 @@ &i2c2 {
 
 	pmic: pfuze100@8 {
 		compatible = "fsl,pfuze100";
+		fsl,pmic-stby-poweroff;
 		reg = <0x08>;
 
 		regulators {