at91, dfu, smartweb: set serial number

since commit 842778a09104 dfu-util shows serial="UNDEFINED".

to see here again a serial number, we have to call
g_dnl_set_serialnumber().

Signed-off-by: Heiko Schocher <hs@denx.de>

board/siemens/smartweb/smartweb.c

@@ -34,6 +34,7 @@
 #ifndef CONFIG_DM_ETH
 # include <netdev.h>
 #endif
+#include <g_dnl.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -256,3 +257,9 @@ void mem_init(void)
 	sdramc_initialize(ATMEL_BASE_CS1, &setting);
 }
 #endif
+
+int g_dnl_bind_fixup(struct usb_device_descriptor *dev, const char *name)
+{
+	g_dnl_set_serialnumber("1");
+	return 0;
+}