BusyBox ip already provides the required functionality and is enabled by default
in OpenWrt. This patch drops the ip dependency and makes the BusyBox ip required
dependencies explicit, allowing for a significant image size reduction.
openwrt-ath79-generic-ubnt_nanostation-loco-m-squashfs-sysupgrade.bin size:
4588354 bytes (with ip-tiny)
4457282 bytes (with BusyBox ip)
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>