drivercore / platform: Convert to dev_pm_domain_attach|detach()

drivercore / platform: Convert to dev_pm_domain_attach|detach()

Previously only the ACPI PM domain was supported by the platform bus.

Let's convert to the common attach/detach functions for PM domains,
which currently means we are extending the support to include the
generic PM domain as well.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>