ARM: dts: add secure firmware support for exynos5420-arndale-octa

Arndale-Octa board is always configured to work with trustzone
firmware binary. Added DTS node entry to enable this support.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos5420-arndale-octa.dts

@@ -26,6 +26,11 @@
 		bootargs = "console=ttySAC3,115200";
 	};
 
+	firmware@02073000 {
+		compatible = "samsung,secure-firmware";
+		reg = <0x02073000 0x1000>;
+	};
+
 	fixed-rate-clocks {
 		oscclk {
 			compatible = "samsung,exynos5420-oscclk";