thermal: tsens8974: Fix delay in the TSENS handler

Add a workqueue to process the status register reads for
the sensors to verify if sensors thresholds are crossed
and send uevent to clients. This change is to avoid any delay
within the TSENS interrupt handler.

Change-Id: I3f3b713a84a6e74fb94e27b8a69be3b1dd0a9dac
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>