driver: thermal: msm_lmh_dcvs: Match the hardware frequency to OPP

The hardware frequency that LMH DCVSh hardware has requested may not
match an actual frequency of CPU. The OSM hardware will aggregate and
match this request to a nearest frequency mentioned in the clock plan.
The current lmh dcvs driver exposes this request without matching to
a frequency value in the OPP table.

In order to reflect the final mitigated frequency, match the mitigation
frequency request from LMH DCVSh to a nearest CPU frequency floor
in OPP table.

Change-Id: Iffc380898eac33f6c30c3808eb38d7bb499f5769
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>