MAINTAINERS: Remove duplicate matching entry

Remove the specific entry for ad5758, since
Documentation/devicetree/bindings/iio/*/adi,* already matches
the path.

Signed-off-by: Ciprian Regus <ciprian.regus@analog.com>
Link: https://lore.kernel.org/r/20220916140922.2506248-2-ciprian.regus@analog.com


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