dt: bcm968580xref: add a spi-nor device

This commit add a spi-nor device in the bcm96850xref device tree.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Kursad Oney <kursad.oney@broadcom.com>

arch/arm/dts/bcm968580xref.dts

@@ -124,3 +124,15 @@
 		label = "green:wps";
 	};
 };
+
+&hsspi {
+	status = "okay";
+
+	flash: mt25@0 {
+		compatible = "jedec,spi-nor";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		reg = <0>;
+		spi-max-frequency = <25000000>;
+	};
+};