dt-bindings: bcm: Add Raspberry Pi Zero W

This adds the root properties for the Raspberry Pi Zero W.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

Documentation/devicetree/bindings/arm/bcm/brcm,bcm2835.txt

@@ -42,6 +42,10 @@ Raspberry Pi Zero
 Required root node properties:
 compatible = "raspberrypi,model-zero", "brcm,bcm2835";
 
+Raspberry Pi Zero W
+Required root node properties:
+compatible = "raspberrypi,model-zero-w", "brcm,bcm2835";
+
 Generic BCM2835 board
 Required root node properties:
 compatible = "brcm,bcm2835";