net: drop !NET_MULTI bcm570x/tigon3 drivers

These drivers have never been converted to NET_MULTI, and they are only
used by one board (BMW).  So drop the drivers until someone feels like
rewriting them for NET_MULTI support.

Rather than punting the BMW board completely, just disable net support
in its board config.  Seems to build fine without it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/configs/BMW.h b/include/configs/BMW.h
index 8398b29..e1951eb 100644
--- a/include/configs/BMW.h
+++ b/include/configs/BMW.h
@@ -49,9 +49,6 @@
 
 #define	CONFIG_MISC_INIT_F	1	/* Use misc_init_f()			*/
 
-#define CONFIG_BCM570x		1	/* Use Broadcom BCM570x Ethernet Driver */
-#define	CONFIG_TIGON3		1
-
 #define CONFIG_CONS_INDEX	1
 #define CONFIG_BAUDRATE		9600
 #define CONFIG_SYS_BAUDRATE_TABLE	{ 9600, 19200, 38400, 57600, 115200 }
@@ -84,6 +81,8 @@
 
 #define CONFIG_CMD_DATE
 #define CONFIG_CMD_ELF
+#undef CONFIG_CMD_NET
+#undef CONFIG_CMD_NFS
 
 
 #if 0