ARM: ux500: Add support for gpio-keys and Proximity Sensor for HREF

Here we ensure the SFH7741 Proximity Sensor is registered through
gpio-keys when booting with Device Tree enabled.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/arch/arm/boot/dts/hrefprev60.dts b/arch/arm/boot/dts/hrefprev60.dts
index 2dd28b9..0756f97 100644
--- a/arch/arm/boot/dts/hrefprev60.dts
+++ b/arch/arm/boot/dts/hrefprev60.dts
@@ -17,6 +17,12 @@
 	model = "ST-Ericsson HREF (pre-v60) platform with Device Tree";
 	compatible = "st-ericsson,mop500";
 
+	gpio_keys {
+		button@1 {
+			gpios = <&tc3589x_gpio 7 0x4>;
+		};
+	};
+
 	soc-u9500 {
 		i2c@80004000 {
 			tps61052@33 {