pci intr config: Fix an off by one bug

pci intr config: Fix an off by one bug

FreeBSD pci_pir.c rev1.105
  We represent PCI intpin's two different ways.  One is the way that the
  intpin register is expressed in hardware where 0 means none, 1 means INTA,
  2 INTB, etc.  The other way is commonly used in loops where 0 means INTA,
  1 means INTB, etc.  The matchpin argument to pci_cfgintr_search() is
  supposed to be the first form, but we passsed in a loop index of the
  second.  This fix adds one to the loop index to convert to the first form.

  Reported by:	Pavlin Radoslavov <pavlin@icir.org>