net: dsa: lan9303: make functions lan9303_mdio_phy_{read|write} static

The functions lan9303_mdio_phy_write and lan9303_mdio_phy_read are local
to the source and do not need to be in global scope, so make them static.

Cleans up sparse warnings:
symbol 'lan9303_mdio_phy_write' was not declared. Should it be static?
symbol 'lan9303_mdio_phy_read' was not declared. Should it be static?
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/lan9303_mdio.c

@@ -67,14 +67,15 @@ static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
 	return 0;
 }
 
-int lan9303_mdio_phy_write(struct lan9303 *chip, int phy, int reg, u16 val)
+static int lan9303_mdio_phy_write(struct lan9303 *chip, int phy, int reg,
+				  u16 val)
 {
 	struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);
 
 	return mdiobus_write_nested(sw_dev->device->bus, phy, reg, val);
 }
 
-int lan9303_mdio_phy_read(struct lan9303 *chip, int phy,  int reg)
+static int lan9303_mdio_phy_read(struct lan9303 *chip, int phy,  int reg)
 {
 	struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);