thermal-core: Re-program the thresholds every time

Program the thresholds every time regardless so we guarantee
the threshold is programmed.  Previous code didn't reprogram
the threshold if it was already believed to be set.  This
check can be wrong is some cornor cases.

Change-Id: Ie94cb40302c585b2b779da57ad70d32cc2445c96
Signed-off-by: Jeff Bernard <jbernard@codeaurora.org>