Thermal: core: Ask .get_trip_temp() to register thermal zone device.

This patch adds a requirement needing .get_trip_temp() callback
function for registering thermal zone device. This function is
used when thermal zone is updated and essential where thermal core
handles thermal trip based only polling way not hw interrupt.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>