net: macsec: allow to reference a netdev from a MACsec context

This patch allows to reference a net_device from a MACsec context. This
is needed to allow implementing MACsec operations in net device drivers.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/macsec.h

@@ -220,7 +220,10 @@ struct macsec_secy {
  * struct macsec_context - MACsec context for hardware offloading
  */
 struct macsec_context {
-	struct phy_device *phydev;
+	union {
+		struct net_device *netdev;
+		struct phy_device *phydev;
+	};
 	enum macsec_offload offload;
 
 	struct macsec_secy *secy;