ARM: dts: twl4030: Add missing madc reference for bci subnode

The twl4030_charger driver expects an iio channel to detect the
presence of an AC charger by looking at VAC (madc channel 11).
This definition is missing in the device tree.
Signed-off-by: Marek Belisko <marek@goldelico.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/twl4030.dtsi

@@ -23,6 +23,8 @@ charger: bci {
 		compatible = "ti,twl4030-bci";
 		interrupts = <9>, <2>;
 		bci3v1-supply = <&vusb3v1>;
+		io-channels = <&twl_madc 11>;
+		io-channel-names = "vac";
 	};
 
 	watchdog {