dt-bindings:iio:gyro:bosch,bmg180: txt to yaml format conversion.

Very simple direct conversion of existing txt file.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Link: https://lore.kernel.org/r/20201031184854.745828-44-jic23@kernel.org