net: fec_mxc: Convert into driver model

This patch add driver model support for fec_mxc driver.

Cc: Simon Glass <sjg@chromium.org>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/fec_mxc.h b/drivers/net/fec_mxc.h
index 0717cc6..9fc6153 100644
--- a/drivers/net/fec_mxc.h
+++ b/drivers/net/fec_mxc.h
@@ -264,6 +264,10 @@
 	int phy_id;
 	int (*mii_postcall)(int);
 #endif
+
+#ifdef CONFIG_DM_ETH
+	u32 interface;
+#endif
 };
 
 /**