stmmac: introduce get_stmmac_bsp_priv() helper

Create a helper to retrieve dwmac private data from a dev
pointer. This is useful in PM callbacks and driver remove.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.h

@@ -30,4 +30,12 @@ int stmmac_get_platform_resources(struct platform_device *pdev,
 int stmmac_pltfr_remove(struct platform_device *pdev);
 extern const struct dev_pm_ops stmmac_pltfr_pm_ops;
 
+static inline void *get_stmmac_bsp_priv(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+
+	return priv->plat->bsp_priv;
+}
+
 #endif /* __STMMAC_PLATFORM_H__ */