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