Add domain crash logic to the generic IOMMU layer to benefit
all platforms.
No spamming of the log can occur. For DomU, we avoid logging any
message for already dying domains. For Dom0, that'll still be more
verbose than we'd really like, but it at least wouldn't outright
flood the console.
Signed-off-by: Quan Xu <quan.xu@intel.com> Acked-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Tested-by: Quan Xu <quan.xu@intel.com>