net:ethernet:aquantia: Fix for RX checksum offload.

Since AQC-100/107/108 chips supports hardware checksums for RX we should indicate this
via NETIF_F_RXCSUM flag.

v1->v2: 'Signed-off-by' tag added.

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