liquidio: Add the features to show FEC settings and set FEC settings

1. Add functions for get_fecparam and set_fecparam.
2. Modify lio_get_link_ksettings to display FEC setting.

Signed-off-by: Weilin Chang <weilin.chang@cavium.com>
Acked-by: Derek Chickles <derek.chickles@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>