A -mm patch caused:

In file included from drivers/pci/quirks.c:532:
include/asm/io_apic.h:61: error: "MAX_IO_APICS" undeclared here (not in a function)

So let's include the needed header.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>