calibration.h: set accel BUCKET_TOLERANCE to 2.5

calibration.h: set accel BUCKET_TOLERANCE to 2.5

The Emdoor I8170 STK8312 accel sensor's Z axis has a
(2.3, 2.5) bias.
Set the accel BUCKET_TOLERANCE to 2.5 to allow compensation
for this sensor.

Change-Id: I39c434d5ba8c9b81558003751dd409b20ef93c85
Tracked-On: https://jira01.devtools.intel.com/browse/GMINL-17695
Tracked-On: https://jira01.devtools.intel.com/browse/GMINL-17696
Tracked-On: https://jira01.devtools.intel.com/browse/GMINL-17698
Signed-off-by: Constantin Musca <constantin.musca@intel.com>
Reviewed-on: https://android.intel.com:443/407030