Allow SIOCGHWTSTAMP to retrieve the current timestamping settings on
DPNIs. This reflects what has been done in dpaa2_eth_hwtstamp_set().
Tested with hwstamp_ctl -i endpmac17. Before the change, it prints
"Device driver does not have support for non-destructive SIOCGHWTSTAMP."
After the change, it retrieves the previously set configuration.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Tested-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> # LX2160A