[PATCH 6/8] pci: provide sensible irq vector alloc/free routines

[Christoph Hellwig]

Hi Bjorn,

I've implemented your suggestion and I'm getting ready to send out
a new version.  One thing that came to mind is:  do you prefer this
code in irq.c or would you rather have it in msi.c?  While it
also has a legacy irq fallback most of it tied pretty closely to
the msi.c code, so I wonder if we should group them together.