media: dt-bindings: imx412: Add regulator descriptions

The imx412 like many I2C camera sensors has three voltage rails which
depending on platform may be necessary to switch power onto directly.

Add in as optional rails so as not to break anything for existing users.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Documentation/devicetree/bindings/media/i2c/sony,imx412.yaml

@@ -32,6 +32,15 @@ properties:
     description: Clock frequency 6MHz, 12MHz, 18MHz, 24MHz or 27MHz
     maxItems: 1
 
+  dovdd-supply:
+    description: Interface power supply.
+
+  avdd-supply:
+    description: Analog power supply.
+
+  dvdd-supply:
+    description: Digital power supply.
+
   reset-gpios:
     description: Reference to the GPIO connected to the XCLR pin, if any.
     maxItems: 1