Sensor: Add more comments for ASensorEventQueue_registerSensor() function

Lets add more comments to clarify that ASensorEventQueue_disableSensor is
to be used same as before for deactivating the sensor with respect to
sensor activation with ASensorEventQueue_registerSensor function.

Test: Check clarification in comments / spell check

Change-Id: Id38c002b57154c1feedf099f45b0ed8ed004ca39
Signed-off-by: Aniroop Mathur <a.mathur@samsung.com>