drivers: thermal: make usage of CONFIG_THERMAL_HWMON optional
When registering a new thermal_device, the thermal framework
will always add a hwmon sysfs interface.
This patch adds a flag to make this behavior optional. Now
when registering a new thermal device, the caller can
optionally inform if hwmon interface is desirable. This can
be done by means of passing a thermal_zone_params.no_hwmon == true.
In order to keep same behavior as of today, all current
calls will by default create the hwmon interface.