thermal: tsens8974: Update polling rate

Update the configurable polling rate at which the sensors
temperature is read from 1.812 seconds to 312.5 milli-seconds.
On faster parts there could be a need to poll the temperature
at a higher frequency to report temperature changes.

Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
Change-Id: If2bceeee55c7210036b3f74db3bc1f32c9c60998