Define acpi_noirq on ia64 since it's used now in pci_link.c.  All ia64
machines use ACPI, so we can just define it to 0 like we do for acpi_disabled 
and acpi_pci_disabled.
Signed-off-by: Jesse Barnes <jbarnes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>