dt-bindings:iio:adc: update the maintainer of vf610-adc

Drop Fugang Duan as the vf610-adc maintainer, and add my self as
the maintainer.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1640073000-32629-2-git-send-email-haibo.chen@nxp.com


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