ARM: dts: twl4030: Add madc

Add madc node to twl4030, so that board DTS
files can simply reference the A/D converter.
Signed-off-by: Sebastian Reichel <sre@debian.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/twl4030.dtsi

@@ -152,4 +152,10 @@ twl_keypad: keypad {
 		keypad,num-rows = <8>;
 		keypad,num-columns = <8>;
 	};
+
+	twl_madc: madc {
+		compatible = "ti,twl4030-madc";
+		interrupts = <3>;
+		#io-channel-cells = <1>;
+	};
 };