de2104x: wrong MAC address fix

The de2104x returns sometimes a wrong MAC address. The wrong one is
like the original one, but it comes with an one byte shift. I found
this bug on an older alpha ev5 cpu. More details are available in Gentoo
bugreport #240718.

It seems the hardware is sometimes a little bit too slow for an
immediate access. This patch solves the problem by introducing a small
udelay.

Signed-off-by: Martin Langer <martin-langer@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tulip/de2104x.c

@@ -1688,6 +1688,7 @@ static void __devinit de21040_get_mac_address (struct de_private *de)
 	unsigned i;
 
 	dw32 (ROMCmd, 0);	/* Reset the pointer with a dummy write. */
+	udelay(5);
 
 	for (i = 0; i < 6; i++) {
 		int value, boguscnt = 100000;