MAINTAINERS: updated Lorenzo's email address

Using my kernel.org email for iio devices.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c75f0e1c683b6ad0333d5504fb00c6f1b14dd1bf.1648114531.git.lorenzo@kernel.org


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