r304459:
  INTRNG: Rework handling with resources. Partially revert r301453.
   - Read interrupt properties at bus enumeration time and store
     it into global mapping table.
   - At bus_activate_resource() time, given mapping entry is resolved and
     connected to real interrupt source. A copy of mapping entry is attached
     to given resource.
   - At bus_setup_intr() time, mapping entry stored in resource is used
     for delivery of requested interrupt configuration.
   - For MSI/MSIX interrupts, mapping entry is created within
     pci_alloc_msi()/pci_alloc_msix() call.
   - For legacy PCI interrupts, mapping entry must be created within
     pcib_route_interrupt() by pcib driver itself.
r305527:
  Fix MIPS INTRNG (both FDT and non-FDT) behaviour broken by r304459