net-next: stmmac: add optional setup function

Instead of adding more ifthen logic for adding a new mac_device_info
setup function, it is easier to add a function pointer to the function
needed.
Signed-off-by: NCorentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -3933,7 +3933,9 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
 	struct mac_device_info *mac;
 
 	/* Identify the MAC HW device */
-	if (priv->plat->has_gmac) {
+	if (priv->plat->setup) {
+		mac = priv->plat->setup(priv);
+	} else if (priv->plat->has_gmac) {
 		priv->dev->priv_flags |= IFF_UNICAST_FLT;
 		mac = dwmac1000_setup(priv->ioaddr,
 				      priv->plat->multicast_filter_bins,

include/linux/stmmac.h

@@ -177,6 +177,7 @@ struct plat_stmmacenet_data {
 	void (*fix_mac_speed)(void *priv, unsigned int speed);
 	int (*init)(struct platform_device *pdev, void *priv);
 	void (*exit)(struct platform_device *pdev, void *priv);
+	struct mac_device_info *(*setup)(void *priv);
 	void *bsp_priv;
 	struct clk *stmmac_clk;
 	struct clk *pclk;