netdev: octeon_mgmt: Make multi-line comment style consistent.

No code changes.  Recent patches have used the netdev style multi-line
comment formatting, making the style inconsistent within octeon_mgmt.c

Update the remaining comment blocks to achieve style harmony.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: David S. Miller <davem@davemloft.net>