Depending on the organization of the ACPI namespace, power resource
device objects may generally be scanned after the "regular" device
objects that they are referred from through _PRn.  This, in turn, may
cause acpi_bus_get_power_flags() to attempt to access them through
acpi_bus_init_power() before they are registered (and initialized by
acpi_power_driver).  [This is not a theoretical issue, it actually
happens for one PnP device on my testbed HP nx6325.]

To fix this problem, make acpi_bus_get_power_flags() attempt to
register power resource devices as soon as they have been found in
the _PRn output for any other devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>