msm: thermal: Update to speed up bootup time

Update KTM driver to remove flush_scheduled_work that
would introduce bootup delay. This patch replaces
cancel_delayed_work with cancel_delayed_work_sync
to cancel a delayed work.

Change-Id: I98ca5a390d5f776267d3b7f2e509f9741fcb932b
Signed-off-by: Shiju Mathew <shijum@codeaurora.org>
Signed-off-by: Dan Trifan <jimsth@gmail.com>