msm: thermal: Add IOCTL interface support to Kernel Thermal Monitor

Kernel Thermal Monitor exposes an IOCTL dev interface, which can
be used for user space cpu frequency mitigation.

CRs-Fixed: 538981
Change-Id: I48ab6be5a9bebee5219c94bdff81badf09576b2a
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>