add clamping of min/max

Ensure that the value of the sensor is clamped to be within the
limits imposed by the min/max of the sensor.  Presently, these
limits may be defaulted by the object definition (to +/- infinity)
or set via config.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Iceaea40daaba1324fd76122843b5520acb4a7726
1 file changed