msm: thermal: Maintain state in the mitigation device monitor

If KTM get a trip threshold trigger notification and if the
temperature stays the same as the recent trip threshold, KTM will
re-activate the recently triggered threshold, resulting in back to
back interrupts. To avoid this add support in KTM to maintain the
recently triggered threshold state and then re-active the threshold
based on the last threshold trip.
This state is updated for mitigation features like VDD MX retention,
CX phase control, VDD restriction, OCR monitor and external clients
like CPR low temperature monitor etc.

CRs-Fixed: 969112 972634
Change-Id: I44c0a93e1507a9f0b8a65e5c2ce5a98962bb335b
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>