PCI/AER: Use managed resource allocations

Use the managed device resource allocations for the service data so the AER
driver doesn't need to manage it, further simplifying this driver.

Link: https://lore.kernel.org/linux-pci/20180918235848.26694-12-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>