Prepare to call setup_io_apic_routing() in pcibios_irq_enable()
also remove not needed member apic_id.

[ Impact: clean up, prepare for future change ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Len Brown <lenb@kernel.org>
LKML-Reference: <4A01C3DD.3050104@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>