With new interface to do plane update on STDU available, use that
instead of old kms_dirty.

v2: Use fence from new resource validation.
Signed-off-by: Deepak Rawat <drawat@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>