ARM: dts: omap3/4: remove unneeded unit name for gpio-keys nodes

This patch fixes the following DTC warnings for many boards:

"Node /gpio_keys/button0@10 has a unit name, but no reg property"

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/omap4-duovero-parlor.dts

@@ -32,7 +32,7 @@
 		compatible = "gpio-keys";
 		#address-cells = <1>;
 		#size-cells = <0>;
-		button0@121 {
+		button0 {
 			label = "button0";
 			linux,code = <BTN_0>;
 			gpios = <&gpio4 25 GPIO_ACTIVE_LOW>;	/* gpio_121 */