atl1c: enable rx csum offload on Mikrotik 10/25G NIC

atl1c: enable rx csum offload on Mikrotik 10/25G NIC

Mikrotik 10/25G NIC supports hw checksum verification on rx for
IP/IPv6 + TCP/UDP packets. HW checksum offload helps reduce host
cpu load.

This enables the csum offload specifically for Mikrotik 10/25G NIC
as other HW supported by the driver is known to have problems with it.

TCP iperf3 to Threadripper 3960X with NIC improved 16.5 -> 20.0 Gbps
with mtu=1500.

Signed-off-by: Gatis Peisenieks <gatis@mikrotik.com>
Signed-off-by: David S. Miller <davem@davemloft.net>