iommu/gart support misses suspend/resume code, which can do bad stuff,
including memory corruption on resume.  Prevent system suspend in case we
would be unable to resume.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Tested-by: NPatrick <ragamuffin@datacomm.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>