mv643xx_eth: fix NETPOLL build

Joseph Fannin <jfannin@gmail.com> and Takashi Iwai <tiwai@suse.de>
noticed that commit 073a345c
("mv643xx_eth: clarify irq masking and unmasking") broke the
mv643xx_eth build when NETPOLL is enabled, due to it not renaming
one instance of INT_CAUSE_EXT in mv643xx_eth_netpoll().  This patch
takes care of that instance as well.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Cc: Dale Farnsworth <dale@farnsworth.org>
Cc: Joseph Fannin <jfannin@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/mv643xx_eth.c

@@ -2112,7 +2112,7 @@ static void mv643xx_eth_netpoll(struct net_device *dev)
 
 	mv643xx_eth_irq(dev->irq, dev);
 
-	wrl(mp, INT_MASK(mp->port_num), INT_TX_END | INT_RX | INT_CAUSE_EXT);
+	wrl(mp, INT_MASK(mp->port_num), INT_TX_END | INT_RX | INT_EXT);
 }
 #endif