mfd: arizona: Update DT binding to support MICVDD init_data

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/devicetree/bindings/mfd/arizona.txt

@@ -42,13 +42,15 @@ Optional properties:
     the chip default will be used.  If present exactly five values must
     be specified.
 
-  - DCVDD-supply : Power supply, only needs to be specified if DCVDD is being
-    externally supplied. As covered in
+  - DCVDD-supply, MICVDD-supply : Power supplies, only need to be specified if
+    they are being externally supplied. As covered in
     Documentation/devicetree/bindings/regulator/regulator.txt
 
 Optional subnodes:
   - ldo1 : Initial data for the LDO1 regulator, as covered in
     Documentation/devicetree/bindings/regulator/regulator.txt
+  - micvdd : Initial data for the MICVDD regulator, as covered in
+    Documentation/devicetree/bindings/regulator/regulator.txt
 
 Example: