msm: thermal: Fix potential memory leak in sensor manager API in KTM

Cancel sensor trip for both high and low thresholds and fix memory
leak in sensor_mgr_remove_threshold API. Modify sensor manager APIs
to use client device to allocate/release memory for thresholds
using devm_kzalloc and devm_kfree.

Change-Id: Icf3b0253d72441e192be5f87c04bdf94799bb036
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>