thermal: tsens: Add timestamp information during tsens_poll

Add timestamp information to check the last instance when
the health monitoring tsens_poll function gets executed.
In addition dump the registers for the temperature five
times with a sleep interval of one measurement cycle to
check if there is temperature variation.

Change-Id: I4f80004ee3329bc6bc9a6950dd74e1c77fcaa030
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>