sh_eth: offload RX checksum on SH7763

The SH7763 SoC manual describes the Ether MAC's RX checksum offload
the same way as it's implemented in the EtherAVB MACs...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/sh_eth.c

@@ -1092,6 +1092,7 @@ static struct sh_eth_cpu_data sh7763_data = {
 	.irq_flags	= IRQF_SHARED,
 	.magic		= 1,
 	.cexcr		= 1,
+	.rx_csum	= 1,
 	.dual_port	= 1,
 };