Document how the ACPI device enumeration code uses the special
PRP0001 device ID.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NHanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>