i2c: bma250: gyro wake: fixing gyro disabled when shouldn't be by mipi off

Let the framework/power off decide about disabling it.
Otherwise some functionality is broken, when only the Mipi panel is off
and not the whole phone sleeps, like when in a call. In call framework
is using not only the proxy sensor but the gyro too to decide if phone
was taken from the ear.

Change-Id: Ib7fa2118feb176c940c1974d8b69045d27814b85