Fix miiphy global data initialization (problem on 4xx boards when no
ethaddr is assigned). Initialization moved from miiphy_register() to
eth_initialize().

Based on initial patch for 4xx platform by Matthias Fuchs.
diff --git a/net/eth.c b/net/eth.c
index b4ff5ef..1646111 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -24,6 +24,7 @@
 #include <common.h>
 #include <command.h>
 #include <net.h>
+#include <miiphy.h>
 
 #if (CONFIG_COMMANDS & CFG_CMD_NET) && defined(CONFIG_NET_MULTI)
 
@@ -136,6 +137,10 @@
 	eth_devices = NULL;
 	eth_current = NULL;
 
+#if defined(CONFIG_MII) || (CONFIG_COMMANDS & CFG_CMD_MII)
+	miiphy_init();
+#endif
+
 #ifdef CONFIG_DB64360
 	mv6436x_eth_initialize(bis);
 #endif
@@ -442,6 +447,10 @@
 
 int eth_initialize(bd_t *bis)
 {
+#if defined(CONFIG_MII) || (CONFIG_COMMANDS & CFG_CMD_MII)
+	miiphy_init();
+#endif
+
 #if defined(CONFIG_AT91RM9200)
 	at91rm9200_miiphy_initialize(bis);
 #endif