From: Bjorn Helgaas <bjorn.helgaas@hp.com>

This consolidates the PCI MSI configuration into drivers/pci/Kconfig,
removing it from the i386, x86_64, and ia64 Kconfig.

It also changes the default for ia64 from "y" to "n".  The default on i386
is "n" already, and I'm not sure why ia64 should be different.