Support recent change moving virtual IOAPIC model into Xen for

Support recent change moving virtual IOAPIC model into Xen for
ia64/VTI. Now ia64/vti will create links to arch/x86/dm/vmx_vioapic.c
and include/x86/vmx_vlapic.h.

Firstly, a small change to common virtual IOAPIC model to be used by
both sides. Also some compilation fix to tools is included in first
one. Secondly, there are ia64-specific changes to hook to common
IOAPIC model.

Based on this patch upon latest xen-ia64-unstable tip, we can see
multiple domains working again on XEN/IA64, including both domU and
VTI domain simultaneously in run-time.

Signed-off-by Kevin Tian <kevin.tian@intel.com>
Signed-off-by Anthony Xu <Anthony.xu@intel.com>
Signed-off-by Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by Eddie Dong <eddie.dong@intel.com>