thermal: qpnp-adc-tm: Check for Timer2 option

Timer2 is a default timer used by the BTM clients for 1 second
measurement polling interval. Handle the condition in the driver
if clients specify the property qcom,meas-interval-timer-idx
for one second.

Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
Change-Id: I396f5e6a34cd632a8217d3a142ae89cf85eb2b5a