intel-iommu: add support for invalidation completion event for Invalidation Wait Descriptor

When IF field is Set in Invalidation Wait Descriptor, VT-d will complete it by
generating an invalidation completion event.
Change the argument list of vtd_generate_interrupt() to be used by both fault
event reporting and invalidation completion event via msi.

Signed-off-by: Le Tan <tamlokveer@gmail.com>