ARM: dts: mt7623: enable SMP bringup

Add support for booting secondary CPUs on MT7623.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>

arch/arm/boot/dts/mt7623.dtsi

@@ -23,6 +23,7 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "mediatek,mt6589-smp";
 
 		cpu@0 {
 			device_type = "cpu";