net:ethernet:aquantia: Fix for LSO with IPv6.

Fix Context Command bit: L3 type = "0" for IPv4, "1" for IPv6.

Fixes: bab6de8f ("net: ethernet: aquantia:
 Atlantic A0 and B0 specific functions.")

Signed-off-by: Pavel Belous <pavel.belous@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>