ARM: dts: imx7-mba7: Enable SNVS power key

This allows using S10 for power down / shutdown.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/nxp/imx/imx7-mba7.dtsi

@@ -554,6 +554,10 @@ &sai1 {
 	status = "okay";
 };
 
+&snvs_pwrkey {
+	status = "okay";
+};
+
 &uart3 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_uart3>;