thermal: ti-soc-thermal: use thermal DT infrastructure

This patch improves the ti-soc-thermal driver by adding the
support to build the thermal zones based on DT nodes.

The driver will have two options now to build the thermal
zones. The first option is the zones originally coded
in this driver. So, the driver behavior will be same
if there is no DT node describing the zones. The second
option, when it is found a DT node with thermal data,
will used the common infrastructure to build the thermal
zone and bind its cooling devices.

In case the driver loads thermal data using the legacy
mode, this driver still adds to the system
a cpufreq cooling device. Loading the thermal data from
DT, the driver assumes someone else will add the cpufreq
cooling device, like the cpufreq driver.

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>