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>
diff --git a/drivers/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c
index f54c450..124d5d6 100644
--- a/drivers/net/tulip/de2104x.c
+++ b/drivers/net/tulip/de2104x.c
@@ -1688,6 +1688,7 @@
 	unsigned i;
 
 	dw32 (ROMCmd, 0);	/* Reset the pointer with a dummy write. */
+	udelay(5);
 
 	for (i = 0; i < 6; i++) {
 		int value, boguscnt = 100000;