PCI/AER: Move aer_irq() declaration to portdrv.h
The aer_irq() declaration is the only thing needed by aer_inject.c. Move
it to portdrv.h so we eventually get rid of aerdrv.h completely. No
functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>