net: sh_eth: add set_mdio_gate in bb_info

The SH7757's ETHER and GETHER use common MDIO pin. The MDIO pin is
selected by specific register. So this patch adds new interface in
bb_info, and when the sh_eth driver use the mdio, the register can
be changed by the function.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sh/include/asm/sh_eth.h b/arch/sh/include/asm/sh_eth.h
index e86c880..0f325da 100644
--- a/arch/sh/include/asm/sh_eth.h
+++ b/arch/sh/include/asm/sh_eth.h
@@ -15,6 +15,7 @@
 	int edmac_endian;
 	int register_type;
 	phy_interface_t phy_interface;
+	void (*set_mdio_gate)(unsigned long addr);
 
 	unsigned char mac_addr[6];
 	unsigned no_ether_link:1;