If writeq() not supported, then do atomic two 32bit write
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Murthy Bhat <Murthy.Bhat@pmcs.com>
Reviewed-by: Karthikeya Sunkesula <Karthikeya.Sunkesula@pmcs.com>
Signed-off-by: Mahesh Rajashekhara <Mahesh.Rajashekhara@pmcs.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>