thermal: netlink: Add genetlink bind/unbind notifications

Introduce a new feature to the thermal netlink framework, enabling the
registration of sub drivers to receive events via a notifier mechanism.
Specifically, implement genetlink family bind and unbind callbacks to send
BIND and UNBIND events.

The primary purpose of this enhancement is to facilitate the tracking of
user-space consumers by the Intel HFI driver. By leveraging these
notifications, the driver can determine when consumers are present
or absent.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>