[PATCH] x86_64 irq: Begin consolidating per_irq data in structures.

Currently the io_apic.c has several parallel arrays for different
kinds of data that can be know about an irq.  The parallel arrays
make the code harder to maintain and make it difficult to remove
the static limits on the number of the number of irqs.

This patch pushes irq_data and irq_vector into a irq_cfg array and
updates the code to use it.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>