ACPI: Take power resource initialization errors into account

Some ACPI power resource initialization errors, like memory
allocation errors, are not taken into account appropriately in some
cases, which may lead to a device having an incomplete list of power
resources that one of its power states depends on, for one example.

Rework the power resource initialization and namespace scanning code
so that power resource initialization errors are treated more
seriously.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>