staging:iio:adis16080: Add device id table entry for the adis16100

The adis16100 is very similar to the adis16080. The driver description already
states that the driver supports the adis16100 as-well. But so far the there is
no device id table for the adis16100 and the drivers does not bind to a device
named adis16100.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>