thermal: cpu_cooling: introduce of_cpufreq_cooling_register

thermal: cpu_cooling: introduce of_cpufreq_cooling_register

This patch introduces an API to register cpufreq cooling device
based on device tree node.

The registration via device tree node differs from normal
registration due to the fact that it is needed to fill
the device_node structure in order to be able to match
the cooling devices with trip points.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
(cherry picked from commit 39d99cff76bf2992fd6dd4b1fc62da139e62e90c)

Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
	drivers/thermal/Kconfig
	drivers/thermal/cpu_cooling.c