ramips: move zyimage creation to include/image-commands.mk
This is required for upcoming Keenetic KN-3911 support
Signed-off-by: Maxim Anisimov <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/16830
(cherry picked from commit 79db5d65ca5a19fb37e7fb428dec798f713a8632)
Link: https://github.com/openwrt/openwrt/pull/18055
Signed-off-by: Hauke Mehrtens <[email protected]>