ramips: add ip17xx support to WLI-TX4-AG300N

ramips/rt288x WLI-TX4-AG300N was missing support for its 100Mbit switch which
should be included by default.

Signed-off-by: Yo Abe <[email protected]>
[Jo-Philipp Wich: picked from OpenWrt PR#359, rewrap commit msg, fix Sob]
Signed-off-by: Jo-Philipp Wich <[email protected]>

target/linux/ramips/image/rt288x.mk

@@ -58,6 +58,7 @@ define Device/wli-tx4-ag300n
   BLOCKSIZE := 64k
   IMAGE_SIZE := $(ralink_default_fw_size_4M)
   DEVICE_TITLE := Buffalo WLI-TX4-AG300N
+  DEVICE_PACKAGES := kmod-switch-ip17xx
 endef
 TARGET_DEVICES += wli-tx4-ag300n