dt-bindings: iio: adc: mcp320x: Use vendor prefix compatible strings

Update the example to use the compatible string including the
vendor prefix instead of the ones deprecated in 3a872138.
Signed-off-by: NFabian Mewes <architekt@coding4coffee.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/mcp320x.txt

@@ -49,7 +49,7 @@ Required properties:
 Examples:
 spi_controller {
 	mcp3x0x@0 {
-		compatible = "mcp3002";
+		compatible = "microchip,mcp3002";
 		reg = <0>;
 		spi-max-frequency = <1000000>;
 		vref-supply = <&vref_reg>;