sdp: call board_usb_init at spl_sdp_load_image

Need initialize UDC before run sdp download
Signed-off-by: NFrank Li <Frank.Li@nxp.com>
Signed-off-by: NPeng Fan <peng.fan@nxp.com>

common/spl/spl_sdp.c

@@ -19,6 +19,8 @@ static int spl_sdp_load_image(struct spl_image_info *spl_image,
 
 	usb_gadget_initialize(controller_index);
 
+	board_usb_init(0, USB_INIT_DEVICE);
+
 	g_dnl_clear_detach();
 	ret = g_dnl_register("usb_dnl_sdp");
 	if (ret) {