iwlwifi: mvm: add thermal throttling and CT kill

In order to avoid NIC destruction due to high temperature,
CT kill will power down the NIC.

To avoid this, thermal throttling will decrease throughput
to prevent the NIC from reaching the temperature at which
CT kill is performed.

Signed-off-by: Eytan Lifshitz <eytan.lifshitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>