iio: st-sensors: add support for single full scale device

Some sensors could have only one full scale value. This means that the
sensor hasn't a full scale register. This commit add a check on the
configured full scale address to support such kind of sensors.

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
1 file changed