move nanopc-t6 recipes above rock 5b.
Fixes: 9482341a47 ("rockchip: add support for nanopc t6")
Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>
Link: https://github.com/openwrt/openwrt/pull/16340
Signed-off-by: Robert Marko <robimarko@gmail.com>