thermal : Remove const to make same prototype

Here, prototype of thermal_zone_device_register is not matching
with static inline thermal_zone_device_register. One is using
const thermal_zone_params. Other is using non-const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>