mdio-gpio: Add reset functionality to mdio-gpio driver(v2).

This patch adds phy reset functionality to mdio-gpio driver. Now
mdio_gpio_platform_data has new member as function pointer which can be
filled at the bsp level for a callback from phy infrastructure. Also the
mdio-bitbang driver fills-in the reset function of mii_bus structure.

Without this patch the bsp level code has to takecare of the reseting
PHY's on the bus, which become bit hacky for every bsp and
phy-infrastructure is ignored aswell.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mdio-bitbang.h b/include/linux/mdio-bitbang.h
index 0fe00cd..76f52bb 100644
--- a/include/linux/mdio-bitbang.h
+++ b/include/linux/mdio-bitbang.h
@@ -32,6 +32,8 @@
 
 struct mdiobb_ctrl {
 	const struct mdiobb_ops *ops;
+	/* reset callback */
+	int (*reset)(struct mii_bus *bus);
 };
 
 /* The returned bus is not yet registered with the phy layer. */