Add a helper macro to iterate over ACPI devices that are flagged
as consumers of an initial supplier ACPI device.
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NDaniel Scally <djrscally@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>