net: gianfar: add missing __iomem annotation

Fix the following spare warning:
drivers/net/ethernet/freescale/gianfar.c:3521:60: warning: incorrect type in argument 1 (different address spaces)
drivers/net/ethernet/freescale/gianfar.c:3521:60:    expected unsigned int [noderef] <asn:2>*addr
drivers/net/ethernet/freescale/gianfar.c:3521:60:    got unsigned int [usertype] *rfbptr
drivers/net/ethernet/freescale/gianfar.c:205:16: warning: incorrect type in assignment (different address spaces)
drivers/net/ethernet/freescale/gianfar.c:205:16:    expected unsigned int [usertype] *rfbptr
drivers/net/ethernet/freescale/gianfar.c:205:16:    got unsigned int [noderef] <asn:2>*<noident>
drivers/net/ethernet/freescale/gianfar.c:2918:44: warning: incorrect type in argument 1 (different address spaces)
drivers/net/ethernet/freescale/gianfar.c:2918:44:    expected unsigned int [noderef] <asn:2>*addr
drivers/net/ethernet/freescale/gianfar.c:2918:44:    got unsigned int [usertype] *rfbptr
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/gianfar.c

@@ -177,7 +177,7 @@ static int gfar_init_bds(struct net_device *ndev)
 	struct gfar_priv_rx_q *rx_queue = NULL;
 	struct txbd8 *txbdp;
 	struct rxbd8 *rxbdp;
-	u32 *rfbptr;
+	u32 __iomem *rfbptr;
 	int i, j;
 	dma_addr_t bufaddr;
 

drivers/net/ethernet/freescale/gianfar.h

@@ -1039,7 +1039,7 @@ struct gfar_priv_rx_q {
 	/* RX Coalescing values */
 	unsigned char rxcoalescing;
 	unsigned long rxic;
-	u32 *rfbptr;
+	u32 __iomem *rfbptr;
 };
 
 enum gfar_irqinfo_id {