sh_eth: add sh_eth_cpu_data::cexcr flag

GEther controllers have CERCR/CEECR instead of CNDCR on the others.
Currently we are calling sh_eth_is_gether() in order to check for this,
however it would be simpler  to check the new 'cexcr' bitfield in the
'struct sh_eth_cpu_data';  then we'd be able to remove sh_eth_is_gether()
as there would be no callers left...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/sh_eth.h

@@ -515,6 +515,7 @@ struct sh_eth_cpu_data {
 	unsigned rtrate:1;	/* EtherC has RTRATE register */
 	unsigned magic:1;	/* EtherC has ECMR.MPDE and ECSR.MPD */
 	unsigned no_tx_cntrs:1;	/* EtherC DOES NOT have TX error counters */
+	unsigned cexcr:1;	/* EtherC has CERCR/CEECR */
 	unsigned dual_port:1;	/* Dual EtherC/E-DMAC */
 };