PCI hotplug: cpqphp: use config space PCI interrupt pin encoding

This patch changes cpqphp to use interrupt pin values just as they
come from PCI config space, i.e., 1=INTA, ..., 4=INTD.

pcibios_set_irq_routing() takes pin arguments in the range 0=INTA, ...,
3=INTD, so we'll adjust the pin just before calling it.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>