Make actual use of the device parameter passed down to
io_apic_set_pci_routing() - to have the IRQ descriptor
on the home node of the device.

If no device has been passed down, we assume it's a platform
device and use the boot node ID for the IRQ descriptor.

[ Impact: optimization, make IO-APIC code more NUMA aware ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F6557E.3080101@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>