PM / runtime: Fetch runtime PM callbacks using a macro

While fetching the proper runtime PM callback, we walk the hierarchy of
device's power domains, subsystems and drivers.

This is common for rpm_suspend(), rpm_idle() and rpm_resume(). Let's
clean up the code by using a macro that handles this.

Change-Id: I1e765836f5655b11ab9d46c1dda937fc053d679f
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: mydongistiny <jaysonedson@gmail.com>
Signed-off-by: Albert I <krascgq@outlook.co.id>