board: mediatek: mt8516: init USB Ether for pumpkin board

Init USB Ether if CONFIG_USB_ETHER is enabled.
Signed-off-by: NFabien Parent <fparent@baylibre.com>

board/mediatek/mt8516/mt8516_pumpkin.c

@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <net.h>
 
 int board_init(void)
 {
@@ -24,5 +25,8 @@ int board_late_init(void)
 		}
 	}
 
+	if (CONFIG_IS_ENABLED(USB_ETHER))
+		usb_ether_init();
+
 	return 0;
 }