thermal: Fix binding problem when there is thermal zone params

The thermal zone params can be used to set governor
to specific thermal governor for thermal zone device.
But if the thermal zone params has only governor name
without thermal bind params, then the thermal zone device
will not be binding to cooling device. Because tz->ops->bind
operator is not invoked in bind_tz() and bind_cdev() when
there is thermal zone params.

Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Jinyoung Park <jinyoungp@nvidia.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>