ath79: ubnt-xm: add rssileds package

In order to make RSSI indicator on the device work out of box,
include "rssileds" package in per-device rootfs image by default
for Ubiquiti XM family.

Signed-off-by: Lech Perczak <lech.perczak@gmail.com>

target/linux/ath79/image/generic-ubnt.mk

@@ -38,7 +38,7 @@ endef
 
 define Device/ubnt-xm
   $(Device/ubnt)
-  DEVICE_PACKAGES += kmod-usb-ohci
+  DEVICE_PACKAGES += kmod-usb-ohci rssileds
   UBNT_TYPE := XM
   UBNT_CHIP := ar7240
   ATH_SOC := ar7241