usb: emul: Remove maxpacketsize in usb_emul_setup_device()

This parameter is never used.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/usb/emul/sandbox_flash.c b/drivers/usb/emul/sandbox_flash.c
index 98d20c0..2f84b36 100644
--- a/drivers/usb/emul/sandbox_flash.c
+++ b/drivers/usb/emul/sandbox_flash.c
@@ -390,8 +390,7 @@
 	fs[2].id = STRINGID_SERIAL;
 	fs[2].s = dev->name;
 
-	return usb_emul_setup_device(dev, PACKET_SIZE_64, plat->flash_strings,
-				     flash_desc_list);
+	return usb_emul_setup_device(dev, plat->flash_strings, flash_desc_list);
 }
 
 static int sandbox_flash_probe(struct udevice *dev)