qed: add missing loopback modes

These modes are relevant only for several boards, but may be reported by
MFW as well as the others.

Signed-off-by: Alexander Lobakin <alobakin@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>