VTD: Remove the check for reserved device scope type

VTD: Remove the check for reserved device scope type

Though we only have four valid types now, the new type may be added in future.
It's better to remove the check and only deal with the type that we can
recognize.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@Intel.com>
Acked-by: Keir Fraser <keir@xen.org>
Add log message for this case.

Signed-off-by: Jan Beulich <jbeulich@suse.com>