arm64: dts: meson: g12a: add secure monitor

Add the interface to the secure monitor on g12a
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-g12a.dtsi

@@ -72,6 +72,10 @@ secmon_reserved: secmon@5000000 {
 		};
 	};
 
+	sm: secure-monitor {
+		compatible = "amlogic,meson-gxbb-sm";
+	};
+
 	soc {
 		compatible = "simple-bus";
 		#address-cells = <2>;