msm: thermal: Add support to monitor only one tsens for VDD restriction

Currently VDD restriction feature monitors all tsens for low
temperature condition. There can be interrupt storm due to
temperature oscillation between trigger and clear thresholds
of all these sensors. It may lead to power issues due to frequent
tsens interrupt wake up.

Add support to monitor only one sensor for VDD restriction feature.
It helps to configure one optimal sensor for this feature if above
mentioned scenario is a concern. Add an optional devicetree property
"qcom,vdd-restriction-sensor-id" to specify sensor id to monitor.
If not defined, monitor all tsens for VDD restriction.

Change-Id: I9a36952cbcb40ebca4de5e8357529842b2f77187
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>