drivers: thermal: lmh: Add snapshot of LMH DCVS driver

Add a snapshot of LMH DCVSh driver from msm-4.9 as of 'commit
<47f9b50df9> ("drivers: thermal: limits-dcvs: Prevent race in freq
limits polling")'.

Change-Id: I53538f50266439da5ba2605c03c820b927b07824
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>