thermal: qpnp-adc-thermal: Add checks for low/high notification

Add checks to ensure the low and high threshold enable
register is checked against the status low and high
register before proceeding to notify the corresponding
clients.

Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
Change-Id: Iecd5e08642415ca50c244efdeebbacf295f82303