Thermal: Fix bug on cpu_cooling, cooling device's id conflict problem.

This patch fixes small bug on cpu_cooling. CPU cooling device has own
id generated with idr mathod. However in the previous version, it swapped
to all same id at last stage of probing as 0. This makes id's collision and
also occures error when it releases that id.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>