at91sam9263ek: fix 'update' script

The old update script uses 'load_addr' which is never set. Use 'fileaddr'
instead which is automagically set by e.g. dhcp.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
cc: Stelian Pop <stelian@popies.net>

include/configs/at91sam9263ek.h

@@ -164,7 +164,7 @@
 	"update=" \
 		"protect off ${monitor_base} +${filesize};" \
 		"erase ${monitor_base} +${filesize};" \
-		"cp.b ${load_addr} ${monitor_base} ${filesize};" \
+		"cp.b ${fileaddr} ${monitor_base} ${filesize};" \
 		"protect on ${monitor_base} +${filesize}\0"
 
 #ifndef CONFIG_SKIP_LOWLEVEL_INIT