thermal: tsens: Apply scaling to temp read from sensor

Thresholds are specified in degrees C, and sensor temperatures are
in milli-degrees C. Scale the sensor temperature to degrees C
before comparing to the threshold value to check if threshold
has been breached.

Change-Id: Id2435b9e3d19d7777769ccd412ce8943dec0d1b6
Signed-off-by: Jishnu Prakash <jprakash@codeaurora.org>