MAINTAINERS: Consolidate Analog Devices IIO entries and remove Beniamin Bia

Emails to Beniamin Bia bounce with no such address so remove him from
maintainers.  After this removal, many entries for Analog Devices Inc
IIO drivers look exactly the same so consolidate them.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio <linux-iio@vger.kernel.org>
Link: https://lore.kernel.org/r/20200903181926.5606-1-krzk@kernel.org


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>