sh_eth: fix dumping ARSTR

ARSTR  is always located at the start of the TSU register region, thus
using add_reg()  instead of add_tsu_reg() in __sh_eth_get_regs() to dump it
causes EDMR or EDSR (depending on the register layout) to be dumped instead
of ARSTR.  Use the correct condition/macro there...

Fixes: 6b4b4fead342 ("sh_eth: Implement ethtool register dump operations")
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

@@ -2089,8 +2089,8 @@ static size_t __sh_eth_get_regs(struct net_device *ndev, u32 *buf)
 		add_reg(CSMR);
 	if (cd->select_mii)
 		add_reg(RMII_MII);
-	add_reg(ARSTR);
 	if (cd->tsu) {
+		add_tsu_reg(ARSTR);
 		add_tsu_reg(TSU_CTRST);
 		add_tsu_reg(TSU_FWEN0);
 		add_tsu_reg(TSU_FWEN1);