iio: frequency: admv1013: add support for ADMV1013

The ADMV1013 is a wideband, microwave upconverter optimized
for point to point microwave radio designs operating in the
24 GHz to 44 GHz radio frequency (RF) range.

Datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/ADMV1013.pdf

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20211221112206.97066-1-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>