KVM: ia64: Mark ia64 KVM as BROKEN

Practically all patches to ia64 KVM are build fixes; numerous warnings remain;
the last patch from the maintainer was committed more than three years ago.  It
is clear that no one is using this thing.

Mark as BROKEN to ensure people don't get hit by pointless build problems.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>