msm: thermal: Add support for emergency frequency mitigation

Add emergency frequency mitigation support to Kernel Thermal
Monitor. This feature enables KTM to mitigate the cpu's max
frequency when the temperature crosses the preset threshold.

CRs-Fixed: 538981
Change-Id: Ifb5b60b11c584d897117832156bb11190b743b1d
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>