thermal: intel: intel_pch: Fold two functions into their callers

Fold two functions, pch_hw_init() and pch_get_temp(), that each have
only one caller, into their respective callers to make the code somewhat
easier to follow.

No intentional functional impact.

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>