MAINTAINERS: Add binding docs for Cirrus Logic/Wolfson Arizona devices

Add device tree binding documentation for the Arizona drivers
to the MAINTAINERS file.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

MAINTAINERS

@@ -11392,6 +11392,9 @@ T:	git https://github.com/CirrusLogic/linux-drivers.git
 W:	https://github.com/CirrusLogic/linux-drivers/wiki
 S:	Supported
 F:	Documentation/hwmon/wm83??
+F:	Documentation/devicetree/bindings/extcon/extcon-arizona.txt
+F:	Documentation/devicetree/bindings/regulator/arizona-regulator.txt
+F:	Documentation/devicetree/bindings/mfd/arizona.txt
 F:	arch/arm/mach-s3c64xx/mach-crag6410*
 F:	drivers/clk/clk-wm83*.c
 F:	drivers/extcon/extcon-arizona.c