BMI160 setTapDetectionThreshold typo

[abelsm2]

In line 821 of CurieIMU.cpp

            bmiThreshold = (threshold - 2500) / 500.0;

I believe the 2500 should be 250 instead.

https://github.com/01org/corelibs-arduino101/blob/master/libraries/CurieIMU/src/CurieIMU.cpp#L821

[bigdinotech]

resolved with 6d3c39d