Fold pch_suspend() and pch_resume(), 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: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: NZhang Rui <rui.zhang@intel.com>
Reviewed-by: NZhang Rui <rui.zhang@intel.com>