sh_eth: offload RX checksum on SH7734

The SH7734 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

@@ -1049,6 +1049,7 @@ static struct sh_eth_cpu_data sh7734_data = {
 	.xdfar_rw	= 1,
 	.tsu		= 1,
 	.csmr		= 1,
+	.rx_csum	= 1,
 	.select_mii	= 1,
 	.magic		= 1,
 	.cexcr		= 1,