arm64: dts: zii-ultra: fix ARM regulator GPIO handle

The GPIO handle is referencing the wrong GPIO, so the voltage did not
actually change as intended. The pinmux is already correct, so just
correct the GPIO number.

Fixes: 4a13b3be (arm64: dts: imx: add Zii Ultra board support)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq-zii-ultra.dtsi

@@ -88,7 +88,7 @@ reg_arm: regulator-arm {
 		regulator-name = "0V9_ARM";
 		regulator-min-microvolt = <900000>;
 		regulator-max-microvolt = <1000000>;
-		gpios = <&gpio3 19 GPIO_ACTIVE_HIGH>;
+		gpios = <&gpio3 16 GPIO_ACTIVE_HIGH>;
 		states = <1000000 0x1
 		           900000 0x0>;
 		regulator-always-on;