ARM: dts: Add temperature sensor to exynos5250-spring

Spotted in the Chrome OS 3.8 based device tree.
Needs CONFIG_SENSORS_LM90.
Signed-off-by: Andreas Faerber <afaerber@suse.de>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos5250-spring.dts

@@ -383,6 +383,11 @@ &i2c_7 {
 	status = "okay";
 	samsung,i2c-sda-delay = <100>;
 	samsung,i2c-max-bus-freq = <66000>;
+
+	temperature-sensor@4c {
+		compatible = "gmt,g781";
+		reg = <0x4c>;
+	};
 };
 
 &i2c_8 {