net: phy: genphy_init can be static

To avoid a warning with W=1 about this function not having a previous
prototype, declare it as static, because it is not used outside of this
translation module.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

drivers/net/phy/phy.c

@@ -463,7 +463,7 @@ static struct phy_driver genphy_driver = {
 	.shutdown	= genphy_shutdown,
 };
 
-int genphy_init(void)
+static int genphy_init(void)
 {
 	return phy_register(&genphy_driver);
 }