sh_eth: enable RX descriptor word 0 shift on SH7734

[ Upstream commit 71eae1ca77fd6be218d8a952d97bba827e56516d ]

The RX descriptor word 0 on SH7734 has the RFS[9:0] field in bits 16-25
(bits  0-15 usually used for that are occupied by the packet checksum).
Thus  we need to set the 'shift_rd0'  field in the SH7734 SoC data...

Fixes: f0e81fec ("net: sh_eth: Add support SH7734")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>