net: fec: fix build error in no MXC platform

build error cause by
Commit ff43da86
("NET: FEC: dynamtic check DMA desc buff type")

drivers/net/ethernet/freescale/fec.c: In function ‘fec_enet_get_nextdesc’:
drivers/net/ethernet/freescale/fec.c:215:18: error: invalid use of undefined type ‘struct bufdesc_ex’
drivers/net/ethernet/freescale/fec.c: In function ‘fec_enet_get_prevdesc’:
drivers/net/ethernet/freescale/fec.c:224:18: error: invalid use of undefined type ‘struct bufdesc_ex’
drivers/net/ethernet/freescale/fec.c: In function ‘fec_enet_start_xmit’:
drivers/net/ethernet/freescale/fec.c:286:37: error: arithmetic on pointer to an incomplete type
drivers/net/ethernet/freescale/fec.c:287:13: error: arithmetic on pointer to an incomplete type
drivers/net/ethernet/freescale/fec.c:324:7: error: dereferencing pointer to incomplete type etc....
Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec.h

@@ -97,6 +97,13 @@ struct bufdesc {
 	unsigned short cbd_sc;	/* Control and status info */
 	unsigned long cbd_bufaddr;	/* Buffer address */
 };
+#else
+struct bufdesc {
+	unsigned short	cbd_sc;			/* Control and status info */
+	unsigned short	cbd_datlen;		/* Data length */
+	unsigned long	cbd_bufaddr;		/* Buffer address */
+};
+#endif
 
 struct bufdesc_ex {
 	struct bufdesc desc;
@@ -107,14 +114,6 @@ struct bufdesc_ex {
 	unsigned short res0[4];
 };
 
-#else
-struct bufdesc {
-	unsigned short	cbd_sc;			/* Control and status info */
-	unsigned short	cbd_datlen;		/* Data length */
-	unsigned long	cbd_bufaddr;		/* Buffer address */
-};
-#endif
-
 /*
  *	The following definitions courtesy of commproc.h, which where
  *	Copyright (c) 1997 Dan Malek (dmalek@jlc.net).