ipq40xx: NBG6617: add usb-ledtrig-usbport to DEVICE_PACKAGES

The ZyXEL NBG6617 USB LED was not working with the default images.
It turned out that kmod-usb-ledtrig-usbport was missing from the
default installation.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

target/linux/ipq40xx/image/Makefile

@@ -236,7 +236,7 @@ define Device/zyxel_nbg6617
 #	this minimum-size. However, the larger image can be flashed both ways.
 	IMAGE/factory.bin := append-rootfs | pad-rootfs | pad-to 64k | check-size $$$$(ROOTFS_SIZE) | zyxel-ras-image separate-kernel
 	IMAGE/sysupgrade.bin/squashfs := append-rootfs | pad-rootfs | check-size $$$$(ROOTFS_SIZE) | sysupgrade-tar rootfs=$$$$@ | append-metadata
-	DEVICE_PACKAGES := uboot-envtools
+	DEVICE_PACKAGES := uboot-envtools kmod-usb-ledtrig-usbport
 endef
 TARGET_DEVICES += zyxel_nbg6617