MAINTAINERS: Add Beniamin Bia for AD7606 driver

Add Beniamin Bia as maintainer for AD7606 driver.
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

MAINTAINERS

@@ -903,6 +903,7 @@ F:	Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
 
 ANALOG DEVICES INC AD7606 DRIVER
 M:	Stefan Popa <stefan.popa@analog.com>
+M:	Beniamin Bia <beniamin.bia@analog.com>
 L:	linux-iio@vger.kernel.org
 W:	http://ez.analog.com/community/linux-device-drivers
 S:	Supported