thermal: Fix hotplug race condition leading to memory corruption.

msm_thermal module made a copy of the CPUFreq policy structure
pointer but continues to try and use it after the core has been
hotplugged (and the original structure is freed). The fix is to
use cpufreq_cpu_get/put instead of copying cpufreq pointers.

CRs-fixed: 342351
Change-Id: I312d8bccc09a5df5805f99fecdc9409d9d4ed2be
Signed-off-by: Eugene Seah <eseah@codeaurora.org>
msm_thermal: Remove error messages from log when core is offline

If msm_thermal is not cancelled and TSENS reports a high temperature,
it might try to limit the frequency, but since the core is offline,
the frequency limit may not happen. We need not report this error.

Change-Id: I579e2329c6fb038d53f2d207a6a832185e633785
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>