thermal: intel: intel_pch: Eliminate device operations object

The same device operations object is pointed to by all of the board
configurations in the driver, so effectively the same operations
callbacks are used by all of them which only adds overhead (that can
be significant due to retpolines) for no real purpose.

For this reason, drop the device operations object and replace the
respective callback invocations by direct calls to the specific
functions that were previously pointed to by callback pointers.

No intentional change in behavior.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>