octeontx2-af: Don't treat lack of CGX interfaces as error

Don't treat lack of CGX LMACs on the system as a error.
Instead ignore it so that LBK VFs are created and can be used.

Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>