Missing IRQ routing assignment panic is excessive

[kallisti5]

If the system is unable to match a PCI device to its interrupt via ACPI information, Haiku raises a panic along the lines of "unable to find irq routing for PCI"

This seems to generally happen on occasional non-essential devices... See #9180 (Express PCI card), #10966(xHCI), #11688 (Encryption controller), #12541 (video decoder), #13381 (IOMMU)

Since in most of the known user reports, the system *should* function more-or-less normally when this issue is encountered... lets not have the OS panic. In some of the tickets above users report a "continue" in the kdl enables their system to finish booting normally.

For now we should just spit out an ominous warning about potentially unusable devices and be done with it.

[kallisti5]

Resolved in hrev51032

[kallisti5]

(In #13381) Worked around via hrev51032