iwlwifi: mvm: add registration to thermal zone

Register to thermal_zone interface and implement the
thermal ops.
The thermal handles the device throttling, and sets the
the temperature thresholds the Thermal Manager would be
notified of crossing.
The thermal interface adds a new thermal zone device sensor
under /sys/class/thermal/ folder.

Signed-off-by: Chaya Rachel Ivgi <chaya.rachel.ivgi@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>